Study Guide
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CR04YY
Introduction
1
Unit 1 Computer fundamentals and
information processing
1.1 Information processing
1.2 The basic computer sys1em
1.3 Types of compvter sys1em
1.4 Primary storage
1.5 Secondary storage
1.6 Input
1. 7 Output
1.8 Software
1.9 Operating syslems
1.1 O Evaluating a oomputer system
1.11 Troubleshooting hardware problems
1.12 Data and Information
1.13 Reliability of cnllne Information
1.14 Data checks
1 .15 Data files
Practice exam quesiions
2
4
6
8
10
12
14
16
18
20
22
24
26
28
30
32
Unit 2 Computer networks and web
technologies
2.1 Networks
2.2 Network hardware and software
2.3 The internet
2.4 Mobile oommunicatlol'l networks
Practice exam queslicns
34
36
38
40
42
Unit 3 Social and economic impact of ICT
3.1 The impact of technology
3.2 Misuse of data
3.3 Computer securtty
3.4 Practical applications
3.5 Impact of emerging technologies
3.6 The world of work
3. 7 Jobs in 1echnolcgy
Practice exam questions
44
46
48
50
52
54
56
58
Unit 4a Word processing
4.1 Editing and formatting text
4.2 Text layout
4.3 Document struelure
4.4 Combining and merging
4.5 Helpful fea1ures
4.6 Mail merge
4.7 Creating a 1able of conten1s
60
62
64
66
68
70
72
4.8 Using forms to collect data
74
Unit 4b Web page design
4.9 Wnat is a website?
4.10 Planning the website
4.11 Crea1ing a web page - oontent
76
78
and design
4.12 Publishing a web page
4a Practice exam questions
4b Practice exam questions
80
82
84
86
Unit 5 Spreadsheets
5.1 Introduction to spreadsheets
5.2 Arithmelic and logical operators
5.3 Calculations
5.4 Functions
5.5 Formatting a spreadsheet
5.6 Copy and Paste 1
5. 7 Copy and Paste 2
5.8 Working with large spreads,,eets
5. 9 Sorting a spreadsheet
5.10 Extracting information from a
88
90
92
94
96
98
100
102
104
spreadsheet
5.11 IF function and multiple wcrkshee1s
5.12 Spreadsheet graphs
5.13 Import to a spreadsheet
5.14 Pivot tables
Practice exam ques'.ions
106
108
110
112
114
116
Unit 6 Database management
6.1 Database terms
6.2 Use of databa=
6.3 Rela1ional databases
6.4 Creating and amending a da1abase
6.5 Input to a database
6.6 Searching a database
6.7 Database outputs
Practice exam queslions
118
120
122
124
126
128
130
132
Unit 7 Problem solving and program design
7.1 Problem solving
7.2 Variables
7.3 Flowcharts
7.4 Logical tesls and decisions
7.5 Loops
7 .6 Pseudocode algorithms
7.7 A well-formed algorithm
7 .8 Conditional structures
7.9 Counter-oontrolled loops
7.1 O Condition-comrolled loops
134
136
138
1t.0
142
144
146
148
150
152
Contents
7.11 Different kinds of condition-
controlled loop
7.12 Logical operators
7.13 Testing
Practice exam questions
154
156
158
160
Unit 8 Program Implementation
8.1 Programming languages
8. 2 Using VBA wtth Excel
8.3 Program development
8.4 Input, processing and output
162
164
166
168
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8.5 Readability and variables
8.6 Finding and fixing program errors
8. 7 Making programs from conditional
170
172
algorttnms
8.8 Making programs wtth loops
8.9 Reading data from a spreadsheet
8.1 0 Working with an array
Practice exam questions
174
176
178
180
182
Glossary
Index
184
186
This S'.udy Guide has been developed exclusively with
the Caribbean Examinations Council (CXC'l) to be
used as an additional resource by candidates, both in
and out of scnool. following the Caribbean Secondary
Education Certificate (CSE~ programme.
It has been prepared by a learn wtth expertise in the
CSEC~ syllabus. teaching and examination. The
contents are designed to support learning by providing
tools to l1elp you achieve your best In Information
Technology and the features Included make it easier
for you to mas1er the key concepts and requirements
of 1he syllabus. Do remember to refer to your syllabus
for full guidance on the course requirements and
examination fonnatl
This Study Guide is supported by a website which
includes electronic activities to assist you In developing
good examination 1echrnques:
• On Your Marks activities provide sample
examination-style short answer and essay type
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feedback from an examiner to show where answers
could be improved. These activities will build your
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• Test Yourself activtties are specifically designed to
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Information processing
LEARNING OUTCOMES
In 1.1, you will see how the
1nfcrrriation trat is produced by
compuler syslems is useful in all
types of work.
What is Information processing?
Information processing (IP) describes tr.e manipulation of information 10
make it more useful for a task. IP usually Involves a computer of some
description. Computers store information electronically in the form of
digltal data. So. IP is about using a compUier to manipulate digital dala
to create Information. That lnformation is used by people or sometimes
machines to comple,e a 1ask.
• Sales data may be processed using a computer to produce graphs
showing sales trends over a period. The graphs are easily read by a
manager who uses the information to make decisions about v>lhich
Items of stock 10 order.
• Seosors on a modern car pick up data about the environment around
the car. The data is processed by a computer built into the car allowing
the brakes to be applied automatically to avoid a collision. That can be
a very useful outcome of Information processing.
Both examples illustrate how useful IP can be in our day-to-day lives.
There are many olher examples, some of which you will learn aboUi in
this section.
Industrial uses
Computers are used to control real-life processes. Examples include
control of environments, control of industrial processes, and even flying
a plane. Process control systems work continuously, witnout a human
operator.
Process control
In order to control a process in this way the computer system must have
tne following features.
• Sensor inpUi: The system must constantly monitor 1he process that
is being controlled. Electronic sensors take measuremen1s and send
them to the processor. AA example might be a motion detector.
• Fast processing: The processing must be very fast. The compuler
must react in real time. For example. tt a computerised autopilot is
flying a plar,e, It must make Instant adjustments 10 the controls.
• Outpul to control devices: The output from the processor will control
devices or machines. For example, the computer might move a robot
arm or regulate the flow of chemicals into a mixture.
Automation
Automation is tne use of process control systems to operate machinery,
typically for making tnings in a factory. Tradttional mechanisation means
factories nave machines that are run by human operators. Modern
automation means the machines can work without a human operator.
Of course, people are still needed, even in automated factories,
for example:
• to plan, program and build the automated system
• to make sure that the machines are working safely
• to deal with unexpec!ed or extreme circumstances.
Commercial uses
Computers are used in offices, shops, banks and otr er commercial
contexts. Data are typically input from tne keyboard, or from machinereadable documents, and the output is on the monitor screen, or as
printout.
Information retrieval
Anolher common use of computer processing in the commercial wcrld Is
to find a single piece of information in a great mass of data. For example,
wnen you use an ATM (sometimes called a 'cash point') the computer
will find your bank record and cheok how much money is in your
account. To do this it must find your account instantly in the records of all
the people with accounts at the bank.
Nowadays, the largest source of stored data is the ln1ernet, and people
frequently need to find Information by searching worldwide using search
engines such as Google.
Information management
\JI/hen data are organised in a strue!ured way it Is easier to find and
reltieve the necessary Information. Many commercial systems are based
on the secure management of data, ensuring it is accurate, up to date
and accessible. In 1. 13, you will learn how data are checked to ensure
they are accurate.
Scientific uses
ACTIVITY
Carry out your own research
into one example of automated
process control. You might
choose an aeroplane 1;1utopilot,
an automated factory machine,
or any other example.
Find out what the inputs to and
outputs from the system are.
Computers are used in many ways to support scientific research:
• to regulate experiments and maintain the experimental process
UNK
• to take measurements, wi'.h precision, over long periods, or in extreme
condttions
Find out more about
• to process results, for example by performing calculations
• to store data and help search for answers
• to present results, for example in graphs. scienliflc papers and
presentations
• to keep records and to snare resutts witn other scien11sts.
The internet: 2.3
Computers at work: 3.6
0~
The basic computer
system
LEARNING OUTCOMES
In 1.2, you Will learn 1he main
components of the computer
and l"ow they work logether 10
form a 'unctionlng system.
The computer system
A computer is a mechine for
lnout
processing data .
t
• Processing means 'changing' or
'transforming' .
Processing 1-+--+1 S,orage
• Data is a collective ierm for fects
and figures, of any kind, including
words. numbers, and even sounds
and images.
KEY TERMS
Processing Processing
mear\S cnanglng data, for
example by ordering I:, sortlng
i;, tral'sformlng It or carrying
out calculations. Tne computer
proce;;ses data to create useful
1nfcrmation.
Data A collective term for facts
.ind 'igures of any kind.
Figure 1.2.1 I Thefunct onsofa
People input data and ins!ructions
coroi;vte, svste'Tl
Into 1he computer, the computer
carries out whatever proce;;sing h
has been instructed to do, and the results are output from the system.
The other key fact about a computer is:
• It stores and processes data In an electronic form.
All computers work using electricity. The data and the processes wtthin
the computer exist in a purely electronic form.
Input lnp.,1 means turning data
and IPstructlons Into electronic
form so they can be processed
by lhe COr'lpJ!er.
CPU The Central Processing
Unn of the computer. This is t1e
herdware component In which
processing takes place.
Output Output means turning
data held In electro 0 ic form wtthin
tre computer system into a form
tnat people can unders,and or
use.
The main functions of a computer system
Computers may oe used for ma1y different purposes. But al computers
carry out four basic functions: input. processing. output and storage.
Input means turning dala and lns'.ructions into electronic form so they
can be processed by the computer.
Processing: the comP'J ler processes input data according to input
lnstrvctions. This happens electronically in lhe Central Processing Unit
(CPU) of the computer.
Output usually means lurniPg 111e results of the processing Into a
form that people can understand or use. Someiimes, the output from
a computer is in a form tnat anot11er computer or device can use. A
computer might give instructions to make a robot move, for example.
Storage means storing Information ready for the CPU to use.
(me soreen)
Information is stored etther electronically or in some other form that a
computer can read (such as magnetic fcrm).
Prooessifig
Computer hardware
Outpu:
(theCPU)
Hardware is a general term for all the pieces of equipment lhat make up
a computer syslem. In general, any part of a computer system that you
Input
(the mouse)
can touch or carry is an item of hardware.
Sto•age
(dsk e:c .)
Figure 1.2.2
Ha·dware
Items of hardware are classified according to tne four basic functions of
the computer system.
• Input devices are used to put information in1o ihe compu1er. For
example, when you type le':ters on a computer keyboard, the keyboard
turns the letters into electronic signals. which are sent 10 the CPU. A
mouse is another example cf an inpl.rt device.
• Processors are found Inside every computer system. In a modern
compu1er the processor is called the CPU.
• Ou1put devices produce results that are useful and useable by people.
For example, a computer screen shows informa1ion as words and
pictures tha1 you can understand, a speaker system may play sounds
and music that you can hear, or a robot will perform useful actions.
These are all examples of outpu1. If a computer produces information
or actions In a form that you can read or use, then 1hls is ou1put.
• Storage devices are used to store data for the processor. For example,
data can be s:ored on a flash drive or a hard disk drive. If you look
at the disk you canno1 see the data - it is in a form that only the
computer can read and use.
KEY TERMS
Storage Storage In a compuier
system Is ihe retention o' data In
electronic form ready fer the CPU
tcuse.
Hardware Hardware Is a
general term for all the pieces
of equipment that make up a
computer system. In general, .i.ny
part of a compu;er system that
you can touch or carry ,s an item
of hardware.
The input, outpUi and storage devices are connec1ed to the processor.
They are called peripherals.
EXAM TIP
Inside the CPU
'"' tne ~.i""'- !::Jou ""'-ignt
be cis~ci to l~st 01"
ciescl"ibe t 11e co""'-po.,,evcts
of &l COIM.puter- S!jStel¾.
/
The CPU
Inside the processor of a
computer tnere are typically
several electronic components.
• The Control Untt passes
instruc1ions to all 1he different
parts of the processor. so 1hat
they carry out the righ11asks,
in the right order.
Dov.,'t fol"get to •=Lucie
tne Cl>vt.
Figure 1.2.3 I The CPU
• The Arithmetic and Logic Untt
(ALU) can perform calculations and transform da1a at lightning speed.
• The main memory (also called 1/ie Immediate Access Storage or IAS)
stores the information that is being processed by tl1e ALU.
These componen1s are joined by electronic connections called data
buses. All 1hese components are electronic and if the povver goes off,
1hey stop work1ng.
The componen1s of the processor are typically fixed to a motherboard.
The mot11erboard has connections to 1he peripherals.
/ ACTIVITY j
Creale a diagram of the
computer you use at sctiool.
Mark at least one inpu1 and one
oi.rtput peripheral. Draw an arrow
to where you think.1he CPU ls.
LINK
Find out more about
Storage: 1.4 a.~d 1.5
Input devices: 1.6
Outp.n devices: 1.7
('~
Types of computer
system
LEARNING OUTCOMES
In 1.3. yol.l will learn how
dl'feren1 types of computer are
vsed ;o carry out different tasks.
Computers are everywhere in our everyday lives. Computers vary in size,
power and cost. Some computers are so large they have special rooms
built to house them. Other computers are so small they can be worn
around a wrist or be hidden away behind the dashboard of a car. In 1.3,
you will learn about different types of computers and lheir uses.
Super computers
There are some computer applications where vast amoun1s of data
must be processed very quickly. These are often scientific or military
applications. NASA, tne American space agency, uses a super compu;er
to plan and control its space missions. Meteorological agencies use
super computers to predict the weather.
Figure 1.3.1
Super computer
Super computers are designed to process more data at much higher
speeds than other compUlers. They must also store large amounts of
data. They are very expensive, costing as much as $100 million to build.
Runnirg and maintenance coSls are also very high. Super computers are
usually built for government agencies or large corporations.
Mainframe computers
A super computer costs between
$50 and S100 mtlllcn to build.
Tf,e power needed to run a single
super compUler costs $5 to $10
million every year.
Some processes are so Important to an organisation that il cannot
operate tt the process fails. These are called business critical processes.
An onlir e ordering system is business critical to an internet shopping
site. A network of ATivl cash machines is business crttical to a bank.
Mainframe computers are used to run business critical systems.
As wtth super computers, mainframes are housed in special rooms
and have large amounts of storage. The processes carried out by
mai'1trames are usually quite simple, so processing speed is less
Important than reliability. Business critical processes must be available all
the time.
Personal computers
Desktop computers are general use computers used in offices,
schools and lhe home. The processor is s1ored in a single metal case
lhat is small enougn to fit on a desk. Input and OU1put devices are
separate components attached with cables.
The desktop compuler can be customised lo sutt the needs of an
Individual. A keen game player can install a graphics card for better
game play. A photographer can install an extra disk drive to store
pholographs. A person wilh disabilities can replace the keyboard
wfih a specialist input device.
KEY TERMS
M icroprocessor lhe
Central Processor Unit {CPU)
of a Modern coriputer.
Microprocessors are very small,
which supports small, light
mobile devices.
Mobile computer devices include laptop computers, 1able1s and
smartphones. Mobile devices are light and small so that they can be
carried easily. The devices eitner have a keyboard and screen built into
lhe case or use a touch screen.
A smaller case and built-in peripherals mean that mobile devices cannol
be upgraded and cuslomised as easily as desktop compulers. With
more internet connections available in public places, mobile devices
mean lhat many people can use the intemel from almost anywnere at
any ••
.1me.
, ACTIVITY
I
Carry out your own Investigation
of super computers. Write a snort
report. Who makes lhem? How
fast are lhey compared with the
computers you use a t school?
Give examples of wha11hey are
vsed for. Some examples you
can start your investigation wrth
are S1.Jmmit and Plelades {NASA).
Figure 1.3.3
Portable tab'et computer
Embedded devices Computer processors are now so small and light,
lhey are built into many personal and household devices from smart
watches :o cars.
An embedded microprocessor makes another device more powerful
and useful. For example, a microprocessor in a car can control fuel
consumption, automatic braking or air conditioning systems. A modern
car may have up to SO microprocessors.
Embedded microprocessors are usually designed to do a single lask and
lheir inpvt and oulput is directly to or from the device they are built into.
Some have lnlernet connectiv"rty.
,,
Primary storage
LEARNING OUTCOMES
In 1.2, you learned tnat lhere Is
a memory 1,,nn (also called ll'e
IAS) Inside the CPU. This is the
primary storage of the computer
system. In 1.4, you will learn
about primary storage.
Types of primary storage
Primary s:orage inside the CPU is very quick and easy for tne computer
to use.
There are two main types of primary storage: RAM and ROM.
RAM stands for Random Access Memory. The RAM s1ores ll1e
current instructions and data that the computer is using.
• RAM is read-write memory (which means it can s:ore new data).
• RAM is volatile, which means if the ocmputer Is switched off, or the
electricity goes off, all the data stored In RAM will be lost.
ROM Slands for Read-Only Memory. ROM stores the instructions to
start up the computer system. These instructions are fixed In the factory
wnere the computer was built.
• ROM is read-only, which means the ins1ructions cannot be changed.
• ROM is non-volatile, so these Instructions are not lost 1•/nen the
computer is turned off.
Nowadays, there are also forms of ROM tnat can be altered after they
leave the factory. These are known as PROM and EPROM.
• PROM means Programmable Read-Only Memory. PROM is blank
whe<1 It leaves the factory, and the lns1ructions are added later by a
programmer. But then they are fixed and cannot be changed.
• EPROM means Erasable Programmable Read-Only Memory. If
EPROM is exposed to ur.raviolet light it is wiped clean, so It can be
reused to store new instructions.
The CPU
Con:ro
Un,t
Man Mer,ory
or IAS
~ 8E1
KEY POINTS
Any system that can exls: In two distinct forms is called a
bi-stable system.
For example, an electric lig'lt can be on or o<f, so it Is bl-stable.
1----- - - - - - - - - - - - - I
,
Secondaiy sto•age
,
:I __________________
s ou:side the cPU
:
J
Figure 1.4.1
Pr rnaiy storage
Computer storage devices are bl-s'.able, and the lnforr,ation is
stored In tr e :om1 of on and off signals,
Binary uses only 1s and Os to represent data. It Is ..sed to describe
,he bl-stable Information.
KEY TERMS
RAM Random Access Meriory. RAM is read-write memory (wt lch
means it can store new data). RAM Is volaiile. which mea"S ii t<1e
computer Is swrtched off, or the electrlc,ty goes off, all the data
s!ored In RAM will be lost.
Read-write memory Storage th.rt ca~ be changed to store new
data.
Volatile storage Uses eleetricity. If 1he electricity is :urned o'f, the
data disappears.
ROM Read-Only Memory. ROM is s!orage lhat cannot s!ore new
data. It 1s fixed.
Non-volatile storage Does no'. need electricity. It holds data even
when tre computer Is 1um!;ld off,
Binary Binary nuribers are wrn;en in base 2. They are ma,de of only
two digrts (0 and 1).
Binary data
RAM and ROM store data and Instructions In binary form, typically as
eleetronic signals that can be ON or OFF.
We write an ON signal as a 1 and an OFF signal as a 0. Oi course tt you
looked irside the CPU you would not see any 1s and Os - this is just
how we write about it.
Bit
ACTIVITY
A single ON or OFF signal (a single 1 or O) ls called a bit. This is short for
Binary Digit.
Byte
A group of btts big enough to store one letter (or other character) is
called a byte. Typically there are eight btts in a byte. Storage capacity is
measured In bytes (see the table).
This much storage
Stores roughly
Exact value
Byte
One character
8 bits
Kilobyte
A thousand characters
1,024 bytes
Megabyte
A million characters
1,048,576 bytes
(exaet usage varies)
Gigabyte
A billion characters
1,000 megabytes
Terabyte
A trillion characters
1,000 gigabytes
Word
The number of bits that can be processed in a single operation wilhin the
CPU is known as a 1/1/ord. Larger and more powerful compU1ers use a
larger word size, which means they do more processing In each operation.
Wme definttions of IAS, RAM,
ROM, PROM and EPROM in your
own words - do not copy what ls
writien here.
LINK
Find out more about
Seccndary storage: 1.5
(''b
Secondary storage
LEARNING OUTCOMES
Secondary storage Is computer
memory lhat is reld outside the
CPU. It is non-volatile: it remains
stable when 1he compu1er Is
turned off, You will learn more
about secondary S'.orage l'I 1.5.
Storage media
Storage media are the physical objects used to store data. Computers
make use ol many different storage media.
How It stores
data
M agnetic
tape
Magnetism (on Sequential access
plastic tape)
(slow)
Read-write access
Removable from
the computer
Hard disk
Magnetism
(on a stack cf
metal disks
inside lhe
computer case)
Direct access
See opposite page
Read-write access for more en hard
Usually fixed in
disks.
one machine
High capacity
Optical
disk
Microscopic
pits burned
into a smooth
surface by a
laser. They
are invisible to
normal vision
Direct access
Read-only access
unless you have
the software to
'burn' new data
on to the disk
Removable
High capacity
CDs are used to
store music and
large data files.
DVDs have even
higher capacity and
are used to store
very large amounts
of data such as
movies.
Solid State Microscopic
Drives
silicon circuits
(SSO)
Direct access
Read-write access
Removable
High capacity
SSD memory
comes In 1he form
of sticks or cards
that can be Installed
into a computer.
Flash drives are light
and fast and are
often used in place
of hard drives in
portable devices.
KEV TERMS
Access Compu1er access to
storage mea"s lnat 1here is a
flow cf data between tr.e CPU
and Storage. Tne CPU can take
data from $torage ('read access')
and put new data Into storage
('write aocess').
• Sequential access The stored
data can only be accessed in
order. A video 1ape is an example
of sequential access. Access Is
slow.
• Direct access Any part of the
siorage can be accessed right
away. A DVD Is an example of
direct aocess.
Capacity The capacity of
storage mea'lS now much data It
can hold.
Access speed How quickly the
processor can read data from
storage.
Interface Tre connection
between any 1Wo systems
or parts which allows them
,o oommvnicate. Secondary
storage is connected to tne
processor via an interface.
Features
Main types
l'ype of
storage
There are many
sizes and types
of tape, but tape
is rarely used in
modern computer
systems.
Cloud storage
Sector: a
Cloud storage uses the internet to transfer data between your computer
and a large remote storage area called a data centre. The advantages
and disadvantages of cloud storage over local storage are:
wedge-shaped
area of d SK
• Individuals and organisations oan buy as much or as ltttle storage
space as they need.
Track: a ring•
shaped area
• For most people cloud storage is cl"eaper. The cost is spread across
many users.
• Data can be accessed from anywhere on any device.
• Data is more secure. II isn't lost if a computer fails, is lost or is stolen.
of dsk
Areasofa hardd s~are
r-iarked out with magnetic
gudel '18S
Figure 1.5.1
Some people worry that data stored in the cloud Is more vulnerable to
theft by hackers.
Hard drive
A hard drive is a stack of metal disks, which can be fixed inside or
external to the main compUler case. It can store a lot of data but you can
only access the data tt you use the computer where It is stored.
The surface of a hard disk is divided into tracks and sectors
(see Figure 1.5.1) by magnetic lines.
The disks spin and a read-write head moves across each disk in the
stack, guided by the track and sector markings. When it finds the right
spot It can read existing data or write new data to the disk.
Solid State Drives (SSD) are faSler, smaller and lighter than hard drives.
They are increasingly being used in place cf hard drives, especially In
mobile devices.
Interface
An interface is the connection between any two systems or parts that
allows them to communicate. Secondary storage is connected to the
processor via an interface.
An interface typically includes:
• a port: tne plug-in slot that lets you connect tne storage medium into
the computer
• a bi..<ffer: a temporary area of memory that holds data while it is being
transferred to and from the processor.
There have been many types of computer interface used in the past. In
modern compU1ers most devices are conneoted using a Universal Serial
Bus (USB) port.
Some specialised ports are still used, mainly where high-speed
conneotions are important. For example, soreens are often connected
to a computer using a specialised port suoh as DisplayPort or High
Definition Multimedia Interface (HDMI).
1Nhen you buy peripheral devices it is important to make sure the device
can connect to your comp.,1er.
EXAM TIP
Y0 u"-g people oftev,, li.ive
~l.i.,,g woyc{s foY ~•ffeYevct
Lte";-s of co»cputey
tqULj>l¾e""1:. 'But »ccllu
suye 1:JOK use tl'oe offi.c•&1L
ttYl¾S, e1s g•ve"' ""' t'1•s
book,, to get f "<lL ""'-&iYfes i.,,
the ex..i"'-.
/ ACTIVITY
I
Investigate at least three lypes of
storage, and write a short report
on eaoh one.
Input
LEARNING OUTCOMES
A comouter processor can
only work w th da:a in a digital
electronic form Input devices
convert ail types of Information
into on/off electrical signals,
wh·ch 1he comovter processor
can use. In 1.6, yoJ will find OU'.
more abo.Jt lnout devices.
Input simple data
• An Optical Mark Reader (OMR) system detects the pos~ion of pencil
marks on a page. OMR is sometimes used 10 mark multiple-choice
exam systems.
• A bar code reader scans the bar code on a product. This represen1s
a code number, which is sent to a Point of Sale (POS) terminal. A
POS terminal has the same function as a cash register or till, but It is
compu1erised.
Input letters and numbers
Character reader
Character readers can tell ,he difference between differen1 letters and
other primed characters, so they can 'read' text into tne computer.
• MICR (Magnetic Ink Character Recogniticn) is used to read numbers on
bank cheques. This input device works by detecting special magnetic ink.
• OCR (Optical Character Recognition) works by recognising the shape
of letters. Old-fashioned OCR systems require special prinling styles,
but modern devices can read all types of printing.
Keyboard
Figure 1.6.1
Pont o' Sa·e ,ermlna
When you press 1he differen1keys on the keyboard you select different
letters and numbers. The keyboard sends electronic signals that
represent the cnaracters you have 1yped to 1he processor.
Point-and-click
Point -and-click devices !el you - 1he user - move a 'pointer' on 11-,e
screen of the compu1er, so yoo can select and click on different choices,
The pointer detects the movement of your hand or finger and 1urns 1hal
movement imo electronic signals, which are then sent to !he computer.
Some input devices worl< by moving them abovt.
• A mouse is moved abou1 on a flat surface and sends a signal to the
ccmpvter as it is moved forv,ards, backwards and from side 10 side.
You click a bu1ton en the mouse to 'select' wnatever ii is pointing at.
• A joystick is typically used with a computer game. Like a mouse, it lets
you move forwards, backwards and from side 10 side.
Other input poin1ers work by touch.
• A touch pad detects the motion of your finger when you touch h,
witllout having to use a mouse or joystick.
• A touch screen detects when you touch the display. This Is an easy
way to select choices from an on-screen menu and perform other
simple tasks. Touch screens are used en smartphones and tablet
computers such as the Apple iPad.
• A light pen lets you draw on a touch screen. It gives you more control,
letting you draw lines and make more precise actions. This type of
device can be used by graphic artists to create computer images.
Some modern computers have very few con1rols, and most of the input
Is done by touching the screen. The Apple iPad is an example.
Input sounds
Sounds such as music and voices can be input to the computer.
• A microphone can be used to pick up voices, music and other sounds,
which are then converted into electronic form to be processed or
stored inside the computer. Musicians and record producers can use
the computer to combine and mix sounds.
• Voice response. Some computer systems can distinguish between
different words and respond to spoken commands. For example, some
modern phones will recognise if you say a name, and automatically
place a call to that person. Voice response can also be useful for
disabled people, who mignt not be able to see the screen or use a
keyboard.
ACTIVITY
lnvestiga,e at least five types o'
Input device, and write a short
report on each 0<1e. Suggest at
least one suitable application
for each device included in your
report.
KEY TERMS
Biometric Biometric systems
recognise a person's physical
charac1eristics, for example
reading their fingerprints or Iris
(eye) scan. They are mainly
used for security purposes,
for example 10 allow access to
banks or military premises.
Input images
Images can also be stored Inside the computer in electronic digital form.
• A digital camera 1akes photos that are stored ln electronic form.
• A web cam is a video camera that records a moving image and sends
the signal over the internet. People use web cams to send video
Images to friends who live far away.
• A document scanner takes a picture of a document and stores tt
as an image. Sometimes this is combined with OCR so that the
scanner can 'read' all the letters on the page and store it as text
that can be edited.
Other types of input
Biometric systems
Biometric systems recognise a person's physical characteristics, for
example, reading their fingerprints er iris (eye) scan. They are mainly used
for security purposes, for example, 10 allow access to banks or milttary
premises.
Sensors and remote control
Robots and automated systems must be able to sense features of the
environment - for example, 10 detect where walls are - in order to move
about and perform other tasks. Sensors measure a range of fea:ures
Including lighl, heat, pressure and so on. and send them to the computer
system .
Figure 1.6.4
A robot using =sors m
the cons:ruction Industry
Output
LEARNING OUTCOMES
Output Is data from '.he computer
in a form that 1s readable by
people or useful lo people.
Without olf.put tnere would be no
point na,~ng a computer at all, so
it 1s very Important.
In 1.7, you will find out about
devices which are used to output
results 'rom the computer.
Types of output
One way to classify output is acoording to how it may be read.
• In :his section, we will look mainly at output that human beings ca,i see
and understand, sucn as printed text or tne display on the computer
screen. This is known as human-readable output.
• Computers can also produce output that can be input directly Into
another computer. Examples are bar codes (see 1.6). This is known as
macnine-readable output.
• In addition, computers can output control signals to machines al"d
other devices. for example, to control Industrial processes. This type of
output is very useful to human beings.
A printed output on to paper Is known as a hard copy. An electronic copy
of a document, for example, on a memory stick or attached to an email,
is known as a soft copy.
Visual display unit
The screen of a computer Is also known as a monitor or Visual Display
Unit (VDU). The image on a VDU is typically made up of many tiny dots of
light. These dots are called pixels.
• A low-resolution VDU has comparatively fewer pixels, and each pixel
Is larger. A high-resolution image is made up of a large number of very
small pixels. This gives a clearer, sharper Image.
KEY POINTS
The most oomr1on types of
monitor use Liquid Crystal
Display (LCD) technology. LCD
uses a tni'l layer of liquid crystals
arranged as a grid of pixels.
Tne screen 1s lit from the back
and eacn crystal acts as a filter
creating a colour image.
The more expensive OLEO
technology weigh$ less 1;1nd uses
less power. It Is used in some
phones and tab4et computers.
• VDUs come in many sizes. Large screens have some advantages,
as the image Is bigger and easier to see. However. a small screen Is
suitable for laplops and other mobile devices.
There are many types of VDU defined by the technology used to
produce tne image. The most common types of VDU use LCD or LED
technologies. Cathode ray VDUs are rarely used now because 1hey
are bt.>lky and heavy and give low quality. There are advamages and
disadvantages to each type.
Some1imes a VDU serves as an input device as well as an output device;
see touol\ screen input in 1.6.
Printer
Printers produce primed otrtput from a comptrter on 10 paper, which can
be read by people. There are two main types of prin1er.
• Impact printers have a print head that strikes an inked ribbon against
the paper. Impact prin1ers 1ypically print one character al a time. The
most common type of Impact prin1er is a dot matrix printer. Impact
printers are now rarely used. They are noisy and the quality is low,
especially for images. They cannot print in colour.
• Non-impact printers produce an image by projecting a S1ream of ink
directly on to the page. The two main types of non-impact printers are
laser and inkjet. Inkjet printers spray dots of Ink to create a page line by
line. A laser primer is a faster and more expensive type of non-impact
printer. Special ink, called toner, is transmitted to the page from a cylinder
or drum, which has been electronically charged by a laser beam. Laser
printers print a whole page at a time.
Both inkjet and laser printers can print in oolour. Printers can be classified
according io speed and quality of priming.
Plotter
A plotter works by moving a pen across a page to create a drawing on
the paper. A plotter creates more precise drawings ,han a printer. Plotters
are used for technical drawings, maps and archttect plans.
EXAM TIP
t:,? "-Ot COV\,fuse O"<tp'-<t
Wttl1
StOYt:lge wl1eV\,
, ,
wnt,~ t:l"' e><am t:l"'5•Ner.
.stol'lfge is i"'formati0 ..,,
l1eLoi '"' a foYm that is
macni"'-' Ytlld,;ibte. Tue
COV\.Ul'\.ts of stoyage CllV\,
be se"'t_to tl1e CPt,t foY
process,~.
Oi«pltl: i.s. Yet:loit:lbLe or
L<Sef,.<L to 11umt:l"" bei~s .
Audio output
As well as visual and printed output. computers can produce sound
signals.
• Speakers broadcast sounds from the computer that can be heard by
many people.
• Headpnones are used when only one person wants to hear 1he output
They oover your ears and cut out other sounds.
• Earphones typically go in only one ear. They are used when a person
wants to be able to hear the computer output, but also respond to
other sounds, such as customer queries.
KEY POINTS
A printer Is sul'.able whe" you need a perrianent record of the
output, W"ich you can take away with you.
Companies that need to produce a lot of olrtput will choose fast
printers.
30 printing
Three-dimensional or 30 printing can be used to print solid 30 objects
In materials such as plastic or metal. The process is sometimes called
additive manufacturing. This is because objects are created by adding
thin layers of material on top of each other. Tne technique has been
used to produce high quality metal parts for aircraft engines. 30 printing
is linked to 30 Imaging where a scanner creates a 30 digital Image of
an object. The digital file can be sent across the world by email to be
printed .
LINK
Find out more about
ACTIVITY
lnvesl igate at least five types of output device, and write a short
report on each one.
Machine-readable inputs
including bar coces ano
MICR: 1.6
C'--0
Software
LEARNING OUTCOMES
You have seen that hardware
Is the term for 1he l:ems o~
equipment tha; make up 1he
computer system. Software
is the term for 1he ins1ructlons
that con1rol 1he operation
of the computer system.
In 1.8, you will learn about
1he main basic functions of
software.
Softw are
As well as data, the computer processor holds ins1ruc1ions tnat con1rol
how tne data are processed. A collection of instructions intended to
produce a particular result is called a computer program. Software is the
general term for ihese instructions.
All software is created by programmers, and it Is held within the computer
in the form of electronic signals. You will learn more about how programs
are crea1ed and how they wcrk within the comp\ller in Unit 8.
Systems and applications software
There are two major iypes of softvl/are: sys1ems and applications
software.
• Systems software conltols 1ne operalion of the computer ilself. An
KEY TERMS
Software A collection of
1nstruclions, ln1ended to produce
a pariicular resuh, is called a
computer program, Software is lhe
general term for 1'19se instructions.
Systems software Systems
software con1rols 1he opera:ior of
the cor1puter itsett. An ex;;imple
wovld be Microsoft Windows.
which allows you 10 wcrk with your
computer files.
Applications software
Applications software e~ables 1he
computer to perfotm sol"le
addttional useful 'unction. An
example would be Mlcrosot: Word,
which allows you 10 create
documents.
example would be Microsoft Windows, which allows you to work with
your computer flies.
• Applications software enables the comp.,1er lo perform some useful
funo1ion. An example would be Microsoft Word, which allows you to
create documents.
Systems software
Systems software Is software that controls the operations of tne
computer system ttself. The main types of systems software include:
• Basic Input and Ott.put: Con1rols the operation of hardware items such
as the keyboard and monitor.
• Operating system: Controls lhe overall function of the computer
sys1em, so that all the parts work logether and you can start up
applica,ions software. Microsoft Windows and Mac 0/S are examples
of operating sys1ems. Find out more abcut operating systems in 1.9.
• Utilities: Utilities are programs that carry out one specialist function thal
helps the computer to work smoothly. For example. a utility could help
you make automatic backups of all your files or c/1eck your email for
computer viruses. Symantec Norton Antivirus Is an example of a trtility.
• Sof1ware development: Systems softv.,are also includes the sof1ware
that allows ycu to create computer programs. An Integrated
Development Environment (IDE) provides a range of tools to help a
programmer create and test programs. You can find out muoh more
about this subjecl in Unit 8.
Most of !he systems software you need is ready-installed on the
computer vl'len you buy it.
Applications software
Applica1ions software covers all the other types of software lhat are
available for computer systems. This software enables all the \JSeful
functions that we perform wilh computers, from word processing, lo
robot control, to games.
On this page you will learn about some cf lhe broad 1ypes of applications
software that are available.
• General purpose software allows a wide range of activilies to be carried
out. An example is a general word processing program, which allows
you lo creale many different 1ypes of documenl frcm leafte1s to letters.
These programs may be bought by many millions of customers. They
offer a wide range of functions, and are generally of lower cost than
other lypes of software.
• Special purpose software is written to perform a single 1ype of task.
Compared to general purpose software it is useful lo lar fewer people.
However, beoause it Is focused on only one activily il is very useful to
its targel group. An example might be the software that an architect
uses to create building designs.
EXAM TIP
-Se cLeciy cibout the
di.ffeYev.ce betwee.-.
custo""--WY<-ttev. softwciye
Cl ""cl custol¾i.sed
softwciYe.
• C«$toMo1.-wntte....
softwci re hcis bee""
"'."cide especi.ciLLtJ foy Cl
s•""9Le busi.,,,ess to use
ci""d i.s "'-Ot gev.eYciLLi:, '
foy sALe to otl-ier users .
. _0«$to~ea softwci re
•s ge"'-eYCIL purpose
soft;wCIYe wloii.ch I-leis
bee"" C1clcipted, fo.,
exci"."'J'Lt _with te"<:plcites
or SLl¾pl•fi.ed ""-t"'-1<
s11stel¾S.
• Custom-written software is created for a single customer by a
computer programmer (or team of programmers). This can be quii e
expensive, but tt is written just for your needs, according to your
lnslructions. A large oompany such as a bank might have its own
specially written compUter systems.
General purpose software
The mos1 commonly used softvvare in lhe world of work is general
purpose software. There are ways of making general purpose
software even more useful to companies.
• Custom'sahon: A company lhat canno1afford to have its own customwritten software might decde lo customise a genera package, This
means lhat a software expert m·gnt be employed to adapt lhe general
purpose software so 1hat It fits their spec al:st needs. Tnis 1s less
expens,ve than wnting new software from scratch.
Tne software that controls tl1e
keyboard, monitor, and so on Is
called 1he 'Basic Input Output
System' or BIOS.
BIOS Is generally Installed in the
compJter ROM in tne faelory
where it was made.
.I
• Integration: Many software companies offer groups of applications
thal can work together 10 offer a wider range of functions. An example
is Microsoft Office, w'nich includes a word processing package, a
spreadsheet, a database, and so on. It is easy lo copy items between
the differenl packages.
You can find out mucl\ more about applications software in
Units 4 to 6.
LINK
Find out more about
/ ACTIVITY
I
Find out about at least three dltferent types of utillty software which
are available to buy, and write a short report on wna1 you found out.
Wnal advamages do 1hese trtilitles offer?
Operating systems: 1.9
Wming programs: Unit 8
Applica1ions softv,;are: Unils 4
to6
<\)
Operating systems
LEARNING OUTCOMES
In 1.8, you learned about the
dif:erence between systems
sofi'Nare and applications
software. One of the main types
of systems sof:ware is the
operelfng systerri - ihe so~ware
lhat oo~,rols the operation o'
lhe computer, a~d allows you to
make use of It.
In 1.9, yo, will fir,d cul more
aboU1 operating systel"ls.
KEY TERMS
GUI The Graphical User
ln:erface (GUI) is how lhe
oompU1er allows you to see
information and give lnstrvctlons
to the computer. II makes use of
a mouse. Icons, Windows and a
polnler.
•
Microsoft V\lindows used ,o be
the most widely used operating
system in the world. tt was
estimated that Windows was
hstalled on 90% of oompi.,ters
in 2010. The growth of tablet
computers ar.d smartphones
has seen Android and Apple iOS
overtake Windows as lhe most
widely used OS.
Microsoft \Nindows Is now used
by only 1a% of all computer
devices. It is s1111 1he dominant
system For laptop a~d desktop
computers.
Functions of an operating system
The operating system is loaded on to tne computer before any other
software. It cocitrols all asp~s of the operation of the computer including
the following functions.
• Memory management: Primary storage (the IAS) holds the data and
instructions currently in use by the computer. The operating system
ensures that the correct data and Instructions are copied into tne IAS
ready to use.
• File management: Data and Instructions are held in secondary storage
as computer files. The operating system organises the files and allows
the user to cnoose which ones to access.
• Device management: The operating syslem controls the operation of
the peripheral devices.
• lnput/oU1put managemem: The computer system receives Input from
devices such as the keyboard, and sends signals to outpu\ devices
such as the monitor. The operating system organises this data flow.
• Process management: A modern computer will typically have multiple
processes under way at the same time. These are organised by the
opera+cing system.
• Security: The operating system oontrols some aspects of data security,
for example the password login to a netwcrk. Learn more aboUi
measures to secure oompU1er systems 1n 3.3.
• User interface: The user interface is the system that allows you - the
user - to Interact wtth the computer, to input instructions and data, and
to receive results.
The user interface
The user interface Includes both !he software and hard\"lare that allows
you -1Pe user - to make use of the computer system.
Hardware interface
Vario1.1s nardware Items make it possible for a person to work with the
compU1er system.
• Items such as a keyboard and a monitor screen are found in almost
every computer system.
• Alternative devices, items svch as a louch screen, may make the
oompU1er even easier to use.
• A non-visual interface, such as voice-based or Braille-based input and
output systems, is designed to help people with restricted vision and
other disabiltties tha1might make tt difficult to use the computer.
• Devices such as autcmated sensors and control devices can work
witnout a human user.
Software interface
The software interface controls how the user works with
the computer.
• Al one 1lme moS1 comp\Jler systems were commanddriven. That means that the user had 10 type commands
into 1he computer, such as 'print document' or 'delete
file' (Figure 1.9.1).
• Nowadays almost all computers use a Graphical User
Interface (GUI), which makes it easier and quicker to
tell the compu\er wha11o do (Figure 1.9.2).
Features of a Graphical User Interface
The GUI makes use of the mouse as well as the keyboard . Here are
some important features.
• Mouse pointer: A small arrow or other symbol that moves on the
screen as you move the mouse.
• loons: Small Images 1hat represent commands, files and storage areas.
They cari be selected and aciivated using the mouse poin1er.
• V~indows: Rectangvlar areas of screen that open to allow access to
files and storage areas.
• Menus: These allow you to piok commands from lists of choices
instead of typing them.
EJ
_
...
•• •
Most applloations so'tware is
written for a parcicular operating
system. This software can only be
used on a computer tnat has tnat
operating system.
If two computer systems oan
make use of the same data and
software 1hey ,ue described as
'Interoperable' •
Menv
Wndow
GUI imertace
Figure 1.9.2
/ ACTIVITY
I
Write a simple guide for students of your own age, explaining how
10 oarry out the following aciivlties using the operating system that
you are most familiar with:
• how to start up a software package such as VVord
• how to open a file that you have made, so that you can make
changes 10 11
• how to delete a file.
LINK
Find out more about
Primary storage: 1.e
Secohdary storage: 1.5
lnpU1 devices: 1.6
Output devices: 1.7
Security: 3.3
(''O
Evaluating a computer
system
LEARNING OUTCOMES
In 1.10. you will learn what
'actors reed to be CO"sldered
when evalva1ing the suitability of
a comp.,ter system for a task.
There are times when you will need to choose a computer system to
carry out a task. When doing this you will need to consider:
• what the computer will be used for
• any special needs the user of the computer may have.
There are five factors to consider when evaluating a computer system for
a1ask.
1. Processing speed
KEY POINTS
Clock speed How fast
Instructions are carried out by a
computer's CPU.
M ulti-core Tne number of
processors used in a CPU. Most
modern comp<ilers use two
processors - this Is called dual
core.
You learned in 1.2 that the computer processing unit {CPU) carries out
ins:ructions one after the other. The speed that instructions are carried
out is set by 1he olock speed of the CPU. Some CPUs are faster tnan
others. A fas1er CPU is important in applications where:
• graphics are important (for example. gaming)
• several programs are being run at the same time.
Clock speed A typical CPU clock speed is up to 2.9 megahertz (MHz).
That is 2.9 billion instructions per second. More powerlul processors will
run faster than that.
Multi-core processor Clock speed is not the only thing that affeCls the
perlormance of the CPU. Modern CPUs use more than one processor to
carry out their work. A dual core CPU uses two processors. It will work
almost tl'Ace as fast as a CPU witn just one processor. Some faster CPUs
use four processors. They are called quad core.
Graphics card Graphical applications such as gaming, photo and
video editing and 30 modelling can use a lot of processing power and
slow a compU1er down. This problem can be solved by upgrading the
computer's grapnics card. A graphics card has its own processor and
memory built in and is only used for graphics, leaving 1he main processor
to carry out other tasks.
Figure 1.10.1
Clraohlcscard
•
4 gigabytes of memory can hold
the equivalent of:
• 2 hours of video
• 1.5 days of dlgttal audio
• 1.25 million copies of the text
on this page.
2. M emory
You learned in 1.4 that the CPU has 1emporary memory called Random
Access Memory (RAlvt) built ln to It. Too little RAlvt will slow t11e computer
down. The amount of RAM you need depends on what you are using the
computer for.
Most modern computers will have 4 gigabytes (Gb) of RAM . That Is
enough for web browsing and office applications and will allow you to
have several windows open at the same time.
Users ol more graphical applications such as photo editors or desktop
publishing may need to upgrade to 8 Gb. High definttion graphics or
video editing. games and 30 imaging applications often need 16 Gb
of RAM.
3. Secondary storage
You learned about secondary storage in 1.5. The nard drive is 1he most
usual type of secondary storage found In computers. A typical desk1op
computer will have a 250 or 500 Gb hard disk drive.
Some applications may need more secondary storage. For example,
professional pholographers or video editors work wtth very large graphics
files. They need more disk space tnan someone storing mainly 1ext files.
Some computers come wtth 1 terabyle disks. A terabyie is
1000 gigabytes.
•
A 500-Gb hard disk can hold:
• 1 million digttal photos
• 125 ft.II movies
• 150 million copies of the 1ext
on this page.
SSD memory
An alterna1ive 1ype cf secondary s1orage is a Solid-State Drive (SSD}.
SSD has several advan1ages ever a hard drive: it is faster, lighter and
more reliable, because tt has no moving parts. SSDs are more expensive
lhan hard drives but the higher speed can be useful In high definition
graphical and video applications and games.
Cloud storage
Cloud storage can reduce 1he amount of secondary storage needed
on a computer. A professional photographer may need to store many
lhousands of high definition Images bUt will only be working on a few
al any time. Most images can be stored on a cloud drive until they are
needed. This is called archiving.
4. Software
Wnen evaluating a system, you should research the software that Is to
be used on It. Software will nave requirements for RAM and, sometimes,
secondary storage tha1 need to be considered.
5. Input and output devices
A computer system is no1 just about the main computer unit. You will also
need to 1hink about input and oulput devices.
Do the tasks the computer will be used for need any special Input or
output devices? Input devices might include a scanner or bar code
reader. Output devices could include a colour prinler to create business
reports that include complex charts.
Also tnink of the user of the system. Do they l'ave any special needs lnat
need special hardware or software?
KEY POINTS
The speed of the CPU ls determined by:
• how many operations are carried out in one second
• how r,uch da1a 1s processed in one cperallof"l
• how quickly Information Is sent to a~d fror, memory.
The number of opera1lons per second is measured In hertz (Hz).
megahertz (MHz) and gigahertz (GHz).
/ ACTIVITY
I
Research and write a
specifica1ion for 1wo compUters:
1 A home computer for a family
that play a lot of HD games
and have a large l1ome video
collection.
2 A computer for a student who
researches assignments on
the ln1ernet and writes and
prints those assignments using
standard office software.
Troubleshooting
hardware problems
LEARNING OUTCOMES
In 1.11, you will learn how
to carry out basic checks to
resolve problems In a 1aulty
computer system.
Modern compt.Jler syS1ems are very reliable. Most computers will run for
years without any problems. When a problem does occur, there are some
simple troubleshooting procedvres you can follow.
Stay safe
Always follow these safety guidelines when troubleshooting:
1 Switcn off power points at the wall before connecting or
disconnecting any mains electrictty cable.
2 Do not open the case of your computer or any other device.
3 Never apply iorce when conn~ ing or disconnecting a cable or
component.
4 Make sure all cables are disconnected before attempiing to move a
device (for example, a primer).
5 Do not lift neavy equipment on your own.
6 If in doubt, STOP and ask for help.
DANGER
High
voltage
Make notes
As you troubleshoot you should make notes to record:
1 the steps you have followed. This will be useful Information to pass
on to a technician if you can't solve the problem.
2 any error messages you see on screen while troubleshooting.
Figure 1.11.1 Stay safe
What to do if:
Your computer will not turn on
• Check that the power cable is connected securely in the back of the
computer case and in the power socket.
• Check that the power socket is switched on. To confirm the socket Is
live, turn off the socket, unplug the computer cable and plug in another
device.
• If there a s\Jrge protector, check whether it needs to be reset.
Once you have confirmed the power cable is connected properly and the
power socket Is live:
• Replace the power cable with one that you know is not faulty. Use a
cable from another device that Is wor1<.ing.
11 the computer slill won't start, then you need to report 1he fault 1o a
technician.
Your printer won't work
If your printer won't start when you press the power burton:
• Follow the steps !isled before.
If your printer powers up on but will nol print:
• Check that the USS cable connecting the printer lo the computer is
properly connected.
• Check the computer screen. If a print cartridge needs replacing, there
will usually be a warning message on screen.
• VVhen you remove a print cartridge always take no'.ice of how the
cartridge lines up. If lined up properly. a cartridge will slide easily into
place. Never apply force.
Figure 1.11.3 MousaandUSBdong e
Your printer or mouse won't work
If the device Is connected by a cable:
• Check the USS cable is connected firmly.
If the device is wireless:
• Turn lhe power switch on the mouse/ keyboard device off then on to
rebool the connection.
• Check that the USS dongle is Inserted in the computer.
• Check whether the batteries in '.he device need replacing .
Your computer monitor isn't d isplaying
If a monitor is faulty:
ACTIVITY
• Check that t11e video cable connecting !he monitor to the computer is
firmly connected.
• Carry out the power checks recommended if the main computer does
not power up.
If there is power to the monrtor you will see a green light on the case. If
lhere is still no display on lhe screen:
• Find the brighlness and contrast controls on the monitor case.
Adjusting them may solve the problem.
Laptop computers
If you are l roubleshooting problems with a laptop computer lhere is an
ex!ra check to carry ou1. Some,lmes, the battery in the laplop Is loose.
Locate the battery and press it firmly inlo place.
Create a poster lttled 'Safe
Trcubleshoo'.lng'. The poster
should fist the steps Siudents
need to take to s1ay safe when
lroubleshooting IT problems.
lllustrale your pOS1er witn s1.,itable
Images.
Data and information
LEARNING OUTCOMES
In 1. 12, you will !ear,, about the
cJifference between c!ata a,r,d
information, ancJ the cJifferent
sources of data that are vsed as
input to oomputer processes.
Data processing
In oomputer stvcJies, the words 'data' and 'in:ormation' are used in a very
particular way.
• Data Is a plural word. It means 'facts'. Data are facts that have not yet
been organised or processed.
• Information is what you get w'nen data are organised 1n a useful way.
When data have been processed they can be more useful and helpful.
Useful, organised data are called information.
Data processing is the action of turPing disorganised data into organised
and useful information.
Examples of data processing
Here are some ways that organising data can make them more useful.
• A collection of cards noting the meanings of words would be cJata. But
tt the words were organised into a single document, in alpnabetical
order, this makes a useful dictionary.
• You might no,e all your friends' names and phone numbers cJown,
bVl if they are organised into an electronic list, this can be used as the
directory of a mobile phone.
• A collection of temperature and rainfall measurements over several
years would be cJata, but if you worked out the yearly and monthly
averages, this could help you predict fU1ure weatner trends.
• A shop might note cJcwn all the sales during the week, but if the
records were properly organised, the shopkeeper could tell what goods
he needed to re-order and how much profit he had made that week.
All of these types o' work can be cJone without using a computer. In
the days before computers were common, this type of work was done
by hand, pemaps using paper ancJ pencil. But computers make data
processing much easier ancJ quicker.
Input, processing and output
You have learned that all computer systems include Input, processing
and outpU1 devices. Each part of a computer system Is needed for data
processing.
• Input devices are needed to enter the data Into the oomputer system.
Read more about data input and how It is checked In 1.14.
• Data are stored in files. Learn more about how computer systems store
data in 1.15.
• The processor organises the data and carries out calculations to creale
information. 11 does this elec1ronically. Learn more about how computer
sys1ems process data to produce useful results in 1. 1.
• Output devices are needed to produce results that are usable. Data
outputs are menlioned throughout this unit.
Data sources
Data are collected and input in many different ways.
• Some raw da1a are collected automatically, for example by electro0ic
ser,sors. Weather data or data on Industrial processes can be coll~ed
in this way.
• Often data are input by typing them in. Muc.>i of what you do on this
course, and work 1hat is done with computers in offices and other
businesses, uses typed inpl.11.
• There are document systems sel up to collect and prepare data for
computer processing.
Documents
\JI/hen collecting data, people typically use a structured document,
wnich makes sure lhal the same data are collected in every case, and
organised in the same way.
• A source document is a struc1ured form that you fill in. Examples are a
medical record form that your doctor fills in, or a laboratory report lhat
a scientist fills in during an experiment. Dala from lhe source document
are typically typed into the computer.
• A lurnaround document is a form !Pal is printed out by the comp01er
and then used to collect data. For example, the computer might
already have a record of the names of pupils In your class, but no1 their
dates of birth. A turnarcund document would be output, showing the
names, wtth space lo add the new data. Ii would then be used as an
Input form,
• MacniPe-readabte documents. Some data - such as bar codes - are
designed 10 be input directly Into the computer without typing. This is
panicularly useful if there is a tot of data to enler very quickly.
• Human-readable documents. It can be most useful to have a
document that can be read by people and by machines. This means
the human computer operator can check the dala by eye, and if lne
automated entry goes wrong, the data can be typed in by hand. You
might have seen this at the supermarket, when the bar code reader
doesn't work.
\JI/hen you learn about databases In Unit 6 you will see how the structure
of a database resembles lhe structvre of a source document or form.
ACTIVITY
Collect examples of forms
and source documents - for
example, from your library, from
within your school, even forms
from newspaper adverts. Wn.at
items o1 data do they collect?
Whal useful Information will be
generated from these data?
LINK
Find out more about
D.ita input devices: 1.6
Data inpJt checks: 1. 14
Data storage: 1.15
Inion-nation processing: 1.1
%
Reliability of online
information
LEARNING OUTCOMES
In 1.13, you will learn row
online data can be Incorrect or
rrilsleading. You will learn sorrie
lechniqves to check the rellab,ltty
of online data.
Much of the data and Information we use today is found on 1he internei.
Google processes more than 3.5 billion searches per day. We use the
information we find to educate ourselves and make decisions, from ,,fnat
to buy to how to vote.
Many lnterr.et searches will lead to information 1hat is accurate and
useful. But many will lead to information that is:
• Incorrect
• out of date
• biased
• malicious.
If you carry out the checks in this section. you will be able to test fer
yourself whether information is reliable.
There are four areas you should check when testlng the reliability of
information found on the interne1.
Wh o owns the site?
Can you trust the person or organisa1ion who has published the
information? You should look for sites that have been established for
some time and which are associated witn organisaticns that have a track
record for reliability and honesty.
KEY TERMS
Citation A description of a
source used when researching
and writing an article or 01her
document.
Examples will include establislied newspapers and news sites,
gcvernment agencies, universities and large charities. Do not rule out
commercial organisations bu1 be wary. The information they provide
could be biased towards their own products.
It should be clear to you who owns the site and what its purpose is.
Wh o wrote the information?
Has the author of the informaiicn pUi their name to the article? If r.ot, be
very wary about the information. It can be a good sign if the author gives
their contact details as well as their name.
Does the author seem to be a,' l expert in the subject? You can check if
the author has writlen any other articles on the same subject. The author
may have given their job tttle.
You should be able to identify and find out more information about the
author.
Can the information in the article be checked?
One of the first checks to carry ou1 is to establish the date the article was
written. If you are researching Information Technology, an article written
five years ago could be misleading. tf you cannot find ou1 when 1he article
was written, you should be wary about tt. It could be out of date.
The author of an internet article will usually include links to other relevam
documents. Follow some of those links. The links should work and link to
sites and articles that pass the same tests you are applying to the main
article.
Many authors will use citations at the bottom of an article. Cttations list
the sources they have researched wnen writing the article. Check these
cnations to find out if they seem reliable.
Figure 1.13.1
Microscope
During your research you will find several articles that Interest you. Try to
check facts in more than one anicle.
You wlll be able to follow Jinks from a reliable art,cle to discover how
honestly it was written.
What does the article look like?
Expect a reliable article to be well written and free from spelling and
grammatical errors. A site that publishes reliable professional information
w,11 probably look professionally designed too.
This does not mean poorly written informaticn should be rejected. Nor
does it mean all professionally produced content should be believed. But:
If an online article looks like it was carelessly written, it probably was.
ACTIVITY
The cnecks In this section will not prove beyond doubt that the
information you are reading online is correct. An article that passes the
four tests is likely to be reliable, but always be wary and be willing to
question the reliability of online information.
Four questions to ask:
1 Is it clear to you who owns the site and what its purpose is?
2 Can you identify and find out more lnformalion about the aulhor?
3 Can you follow links from a reliable article to discover how hcneslly it
was written?
4 Is 1he article well written and well presented?
Think of a subject you are
Interested in and carry ou1 an
online search using a search
engine. Pick an article 'rom the
list presented by the search
engine. Carry out the four tests
In 1his section. Do you think the
site you found is reliable? Do you
have any concerns about tt? Give
your reasons.
Data checks
LEARNING OUTCOMES
In 1.1 c., you will learn about the
methods tna, are used 10 ensure
that the oata {that are lnp~t :o a
computer sys:em) are accurate.
Data checks are \..Sed to make
sure tha'. l<icorrect data are not
entered by mistake. lre ~o
r>1aln types of date, check are
verification and Validation.
Why data checks are important
The wnole computer sys1em will go wrong tt tt has 1he wrong input.
Typically data input ls carried out by human operators, perhaps using
a keyboard. Human beings can easily make mistakes. For this reason,
checks are often carried ou11o make sure there are no errors.
Types of error
The user migm type the wrong character on the keyboard. This is called
a 1ypographical error. Scme of 1he most oommon errors are:
• spelling mistakes , because you are not sure how a word should
be spelled
• typing t1'e key next to the one you meant 10 press (such as typing
'amd' instead of 'and')
•
There Is a 'amiliar saying among
computer scientists: 'Garbage
In, Garbage Out' (abbreviated to
GIGO).
This means tnat If the input to a
computer program Is wrong, then
the output will always be wrong too.
• transposttion errors - typing two characters in the wrong order (such as
typing '1eh' instead of 't'r e')
• pressing the Shift Key, or forgetting 10 press it ('or example, 1yping %
instead of 5)
• mixing up numbers and similar-looking letters, such as 1 and I, or 0
and 0.
Proofreading
tf you are typing texl it is relatively easy to spot your spelling mistakes by
reading your document carefully, on the screen. Some people prefer to
print their work out and read tnrough, marking up any mistakes with a
pen. This is called proofreading. If you ever have an important documem
10 prepare, such as an essay, always lake some time to proofread it.
Word processing software typically includes a spell checking
faciltty which checks what you have typed against a dictionary of correct
spellings.
Clia,,les Babbage was an early
inve<itor of comoulers. Someone
once asked 'Pray, Mr Babbage, ff
you pul Into the machine W'Or.g
t gures, would t~e rignt answers
still come oJt?'
He said that wo~ld be Impossible!
11 is much more difficult 10 spot errors in lists of numbers. Proofreading is
harder and spell checking will not help.
Verification
To verify means to double-check that something is true. For a
verification check 1he data inpul is carried oU1 tvvioe - for example, a
password is typed twice. Tne computer checks l hal the two versions are
exactly the same.
Verifica1ion is most useful:
• if the string of characters (letters or numbers) 10 be entered is quite
short, so tha1 It doesn'1 1ake 100 long to enter It a second time
EXAM TIP
• if It is very important that there isn't tne smallest error or change in what
yo-< s.houLol -<111.oleirs.tA i'\d
ls en1ered, for example if you are enlering a bank account number
• if the da1a are hard 10 check just by proofreading. for example a list of
numbers.
You would not use verification to check a whole essay. You might use
verifica1ion to check a password or a code number.
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olatA CA"" be cf.1eck.eol. ALs.o
";""cl.tYsta vcol H,e oli.ffeye""t
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wou:cl. ""-A k.e 1::fO"' c'1oos.e a
J>A'.'1=•cuLAy l¾t t'1ool AS. IM.Os.t
s.1,utAbLe foir 1::1ouy 111.eecl.s..
Va lidation
Validation is a check tha! the data are valid. Valid means the data are of
1he right general type or value. Validation is useful when you do not know
exactly what da1a are to be entered. bu1 you know wha1 sort of data 10
expect.
Here are the main types of validation.
• Data type: The compu1er checks ,ha1 the data are of the righ1 type. For
example, if you are entering your surname, it won't have numbers in it. If
you are entering your age, h won't have letlers in It.
• Range: The computer checks tha11he data are within a sensible range
of numbers. For example, If a school pupil enters their age, you can be
sure the answer will not be less than 3 or more tnan 20. VVhat would
the valid age-range be for pupils In your school?
• Field length: In some cases the number of characters to expect Is
known in advance. An example is a code number such as a bank
account number. The computer checks you have not entered too many
or too few characters.
• Consistency: The computer might check the da,a entered against
o1her records. For example, if you have entered your name be'ore, 1he
compu1er mignt check tha1 you nave entered tne same name.
• Reasonableness: Depending en the 1ype of information you are
en1ering the computer can carry o\11 a number of o1her checks
tha1 your data are reasonable. For example, an age can't be a negative
number.
KEY TERMS
Verification To verify means to
do.ible-check tr.al somelhing is
true. Fer a verification C.'leck '.he
data Input is carried out twice for example, a password Is typed
tvvlce. Tile computer checks tnal
the two versions ere exactly the
same.
Validation Valiclailon is a check
thal tne da:a entered into a
computer are valid. Valid rneans
the data are of 1he right general
type or value,
ACTIVITY
A bank asks users 1o enter their name, age, bank acco,m1 number
and phone number.
• Which two of these tterns are most suitable !or a verification
check?
• Explain three different validation checks that you could use to
check these answers.
LINK
Find out more about
Data security: 3.2 and 3.3
Spelling creeks: 4.5
%
Data files
LEARNING OUTCOMES
Data files
In 1.15, you will learn abov~ how
informa!io" Is stored i" 'lies.
All information is stored in the computer in named files . Any type of
information can be stored as a file - a document, a picture or a sound
clip, for example.
But 1o1men we talk about 'da1a files' we typically mean large collections
of facts (data) stored in an ordered way. This collection of da1a Is called
a database and 1he software used to work with the database is called
Database Management Software (DBMS). You will learn more about
using DBMS in Untt 6.
Data are stored in a da1abase as a series of records. Eaon record holds
the data on a single object, thing or person. For example, In a library
database each reoord will store the information about one book. In a
school database each record will store in:orma1ion about one pupil, and
so on.
Storage media
In 1.5 you learned about different storage media. Some media, suoh
as tape, only allow sequential access. Most modern storage media such as hard disk drive, DVD or flash memory - allow direct or random
access. That means the computer can look quickly a1 any part of the
storage medium. Tapes and o1her sequential media wnich need 10 wind
backv11ards and forwards are rarely used.
File organisation and access
EXAM TIP
6 XC1""'-'"-tYs Ytport tl1cit
50 ""'-e ccivcdiolcites cire
L<"'-CLeC!v about tke
diffeye=e betwee"" ci
seque"'-tLC!L fi,Le Clv,,d Cl
seYiciL fi,Le. Mcii<Ge sure l:J01<
Yecid, civcd uv..derstcivcd t'·
·
Yt LS
sec ho"", ci vcd ,-e"""e""'-bey it
fo Y t ne GX ci """.
Compu.ers generally have pnysical access to all areas of secondary
storage. The compt.Jler can read any file in storage ar,d go directly to any
record in the file.
But software systems are needed to access the stored data. In Unit 8
you will learn about storing data (for example, using an array). You will
learn how to write a program to search through an array to find a pieoe of
information.
Different types of software access data In different ways.
Serial access
In a serial access file the data records are stored as a series, one
after the other. They are not stored in any particular order. To find
Information, the software needs to look through every record, one at
a time.
Sequential access
A sequential access file is like a serial file, but tne records are sorted into
a particular sequence. This makes it easier and quicker for the software
lo locate the correct record when it is needed. The records might be
sorted in code number order, for example.
One problem with sorted sequential files is that na new record is added,
the records have to be sorted again. With a big file this can be a slow
process.
Indexed sequential access
A sequential file Is sorted ln1o a particular order - typically code number
order. But what if you want to find a record using some other information
instead of code number? To help with this type of search a sequential file
often has several indexes attached to it.
/ ACTIVITY
I
If you were creating a database
to store information for a library,
wha1 information would you store
about each book?
In what order would you sort 1he
book re-."Ords?
An index can be added to a
sequential file to help to find
records in the database. What
useful Indexes might you add to
ttie library database?
• An index in a book lets you lock up a panicular key word or
topic and tells you what page of the book has Information about that
topic.
• An index in a da,a file lets you look up a fact in the data file and tells
you what record In tne database has that fact in it.
An index added to a sequential file makes it quicker for the computer to
find the l'lforma11on you need .
Direct or random access
A direct access database will allow the computer to immediately access
lhe location in memory where any record is stored. Tl1ls ls done using an
algortthm that calcula!es the storage location of the record and reads the
information from that location into active compuler memory.
Use of different file types
Different types of i ile are suitable fer different purposes.
• Use a sequential access file in cases where the compuler needs to
lock through every record in the database. An example is a payroll
program. The payroll database will contain a record for each employee
in the company. \l\lhen calculating pay, the database software will
process every record, in order.
• Use a direct access file when the computer has to qulck1y find or.e
record in a large da1abase. An example is a supermarket point-of-sale
terminal. The shop database will contain a record for each product in
the store. \l\lhen a bar code is scanned the computer must immediately
find the price of that product in the database.
LINK
%
Find out more about
Storage systems: 1.5
Database software (DBMS): 6.4
SECTION 1: Multiple-choice questions
1 Vvh,ch of these is lhe most appropriate
computer oomponent to store data In electronic
form for future use?
6 tt a file allows direct access. what does that
c
Laser pri,ter
mean?
a Tne computer has read-o~ly access to
1he file
b Tre computer can Immediately read any
record in the file
d
Mouse
c
Hard drive
b RAM
a
2 One advantage of using a CD for data storage Is:
It is primary storage
b It is human-readable
a
c
It can be reused
d
It Is read-only
3 Main memory Is also referred to as:
ALU
b CU
a
c
CPU
d
IAS
4 \1\/hich of the following Is a device Interface used
Tre file is printed ou1 so you can read it
directly
d You do not need a password to access the
file
7 Which of tnese features is essemial for a
process control application?
a Human-readable documents
b WI-Fl conr ectMty
c Sensor lnpU1
d Grapnloal interlace
8 Typing two lehers in the wrong order ls a<1
example of:
a ,ransposition error
in a computer system?
a SSD
b
c
(lata verification
proofreading
Hard disk drive
USS
d
data rype error
b
C
d CDROM
5 Which of the following statements is TRUE about
ROM?
a New data can be written to ROM
b H is non-volatile
c The conten1s are lost when \he computer Is
turned off
d It is volaiile
9 Which of 1ne following is an appropriate
application for a super compuler?
a Word processing
b Weather forecas:ir g
c 3D gaming
d Payroll PfOOBssing
10 A grap" ioal user interface usually consists of:
a Pascal commands
b video cllps
c DOS commands
d Icons
/ Fvrther practice questions
and examples can be found at
www.oxfordsecondary.
com/97801984372 15
II
a2
a
0
SECTION 2: Structured questions
1 a
Explain the functions of:
ii
The Control Unit
The Arithmetic ar.d Lcgic Unit (ALU)
Ill ROM
b What other 'orms of ROM are available?
Vvhat are their fealures?
2 a
Explain the uses of 1he followlrig input
devices:
web cam
ii
MICR
iii bar code reader
iv biometric systems
b
Give an example of 1<1mere eaeh m1ght be
vSed.
3 An insurance company uses human operators to
enter data into the compvter using keyboards.
Explain why good data checks are Important to
this company.
4 What is cloud storage? List three reasons you
would choose to s!ore your data In the cloud
rather than on a hard disk drive.
5 Match each statement in Column A to an Item In
Column B.
A
B
Uses sequemial access
Flash memory card
Common compu;er port Magnetic tape
Divided Into sectors
CD-R
Used In d gltal came-as
Hard drive
Optical disk
USB
6 You start your r ome computer but find there is
no Image on tne screen. Briefly describe three
troubleshooting checks you can carry out to
correct lhe problem.
Further practice questions
and examples can be found a:
wvvw.oxfordsecondary.
corn/9780198437215
Networks
LEARNING OUTCOMES
Nowadays, very 'ew ccmputi,rs
are used as 'stand-alone'
machines. Computer
communications are very
impor:ant. Comp-,ters can be
connee1ed to ofner comp..,1ers,
in a network, and most of the
computers In the world are
connec:ed to the Internet.
In 2.1 , you will learn about
lhe technology used to join
computers ;ogetrer - network
,echnology,
In this unit, you will learn about computer networks Including the Internet.
You will learn about the hardware, software and protocols that are
needed 10 ensure networks operale.
At the end of the unit are some practice exam questions to test your
knowledge.
Networks
A computer network is any system that allows oompu1ers to send signals
to other computers in electronic form. The signals are sem in a variety o!
different ways, and a range of differen1 technologies are used.
Types of network
Networks can be defined by the size of area that is covered by tt:e
network. There are three main types.
• A Local Area Network connects computers wtthin the same building,
or at most within buildings that are close together (for example, a
scticol).
• A 1Nide Area Network oonnects computers that are spread out over a
large area svch as an island, the whole Caribbean, or even across the
ocean.
• A Melropolitan Area Netvvork is slightly less common. It might oonnect
the computers in a large city, or a district.
Transmission media
Sometimes networks are connected by physical cables that transmit the
electronic signals between computers.
• Figure 2. 1.1 shows a twisted pair cable. This type of cable is made
up of pairs of wires. In each pair the wires are twisted around each
otner. This type of cabling has been used for many years. It is relatively
inexpensive and reliable.
Figure 2.1.2
Coaxia! cabe
• Figure 2.1 .2 shows a coaxial cable. This type of cable is made of an
inner oonductlng cable surrounded by insulation. It is more expensive
than twisted pair cable bu1 provides better insulation against electrical
interference.
• Figure 2.1 .3 shows a fibre-optic cable. Fibre-optic cable sends signals
in the form of light pulses. Fibre-optic cable is faster than twisted pair
cable and can be used over longer distances. It is usually used to
connect major items of hardware svch as hubs and swttches. You will
learn more about hubs and switches In 2.2.
• Most modern networks use a mix of copper cable and ~bre-optic
cable where higher speed and longer distance Is needed.
Figure 2.1.3
Flore,o:,Vc cab'e
Wireless connections
Other network technologies send signals without the use of wires
or cables.
• Infra-red signals: Infra-red is a form of light that cannot be seen by the
numan eye. Infra-red signals can be used to connect items that are
close together, typically in 1he same room.
• Micrcwave signals: Low-intensity microwaves are a form of radio signal
and can be used for communication. They work over longer distances
than infra-red but need a clear line o' sight with no solid obstacles
between the wireless transmitters and receivers.
• Satellite !inks between sa1ellttes in orbit and aerials often use
microwaves, because t11ere are no solid obstacles between the earth
and sky.
••
Wi-Fi Is used by over 700 million
people. There are over 7!;>0.000
\/\Ii-Fi hotspots around the world,
Wireless protocols
To enable devices and computers to 'talk' to each other there are several
sets of agreed communications standards. These standards are called
protocols. For example:
• Bluetooth is a wireless technology standard for communicating over
short distances using short wavelength radio tra'lSmlssions. h is typically
used to connect wge1her devioes tha1 belong 10 Ire same person.
• Wi-Fi is a se1 of communication star dards tna1 allows computers to
KEY TERMS
Network A computer network
is any system tna'. allows
compV1ers ;o send signals 1o
o:her computers in electronic
form.
connect to a network or the internet through wireless signals. A Wi-Fi
enabled computer can connect to a network when within range of a
wireless router or wireless access point. A hotspot is a place in range
of a WI-Fi connection. If you are localed in a 'hotspot' you can connect
wirelessly to the inten.,e'..
Bandwidth
The amount of data ihal can be sent via a connechon is called tts
'bandwdth'. Broadband connections can carry s.g~s with a lot of data,
such as vioeo s.gnals. Narrowband connections lake longer to send
moving images and large pictures. They are mostly used for 1ext-based
messages, Vo:ceband connections make use of the phone line; these are
very na·rowband and ,he connection is typ cally qu te slow.
Communication terms
• Simplex commun-callon sends S'Qnals 1n one d rection on¥ (for example,
ACTIVITY
a television, where you ca1 receive programs, but not send messages).
• Duplex communication sends signals in both directicns (for example,
a computer connected to the inlernet that can receive and send
information).
Research the compit.er ne1wor1<
in use al your school. What
technology is used?
• Half-duplex communicaiions wori< in both directions, but only one at
Are there any Wi-Fi hotspois near
to where you live 7
a time. An example is a walkie-talkie, where only one person can talk
at any time.
• Point-to-point communication connects two fixed points, and olher
users cannot hear the signal. An example s a phone conversation.
• Broadcast communication is sent out from a central point, and
anyone who can pick up the signal can hear it. An example is a radio
station, which can be heard by anyone with a radio.
LINK
Find out more about
Tne imernet: 2.3
%
Network hardware and
software
LEARNING OUTCOMES
Network hardware
In 2.2. you will learn about ll'le
hardware and software needed
to make a network operate.
In 2.1, you learned that tne devices in a computer network can be linked
togelher with cables or by using wireless connectioflS. Linking devices
toge'.her is not enough to make a network. Special network hardware
and software is also needed.
A computer network needs special hardware to connect devices
toge'.her. The main network hardware devices are:
•
•••••••• •
• Hub A hub Is placed at !he centre of a network. It is used to connect
devices together. When a hub receives data, it sends it out to all t11e
devices connected to it. Each device checks network messages and
accepts data addressed to it.
Net,vor'< hub
• Switch A swttch is a special kind of hub. A swttcn works out which
•
device data is for and only sends tt lo that device. A switch is more
expensive to buy and operate bl.11 is laster and more sect.re.
• Bridge A bridge Is special type of swttch designed 10 connect one
Local Area Network (LAN) 10 another so that they act as a single LAN .
• Router A router is used to connec1 a LAN to the internet. A router
allows an organisation lo se11d email across the internet and 10 link
sites in different cities and countries together. Most home internet
connections use a router.
• Modem Data Is sent across the internet using public networks such
as telephone systems. Public networks use different data formals to
those used by a LAN. A modem Is used to convert the data between
the two formats so that tt can be understood and used in 1he LAN.
Modem is shortnand fer modulator / demodulator.
Figure 2.2.1
••
•
•
•
•
A wfreless network uses special
hardvvare devices called Wireless
Aooess Points or VI/APs for short.
A WAP is connected tq a nelwork
hub or switch by cable. T11e WPP
:ransmlts a wireless signal 1o allow
devices such as tablet computers
'.o access the LAN. You may see
1hese In your SC'10ol, US.tally high
on a wall or on the ceiling.
• Network interface card (NIC) All devices that are attached to the
network need an NIC. Most modern devices such as compulers and
printers have a NIC built in so they are ready to be connected lo tile
network. An NIC ls sometimes called a network adapter.
Figure 2.2.2
Network Inter.ace card
Software
A network ls not Just about hardware such as hubs and routers. It also
needs software to operate successfully. The main software required in a
LAN are:
• Network operating system The operating sys1em installed on
network compU1ers must support operations such as network printing
and sharing files. Networks are now so common 1"81 these functions
are buitt ln1o most s1andard operating systems such as Microsoft
Windows.
• Network management software This is utility software tnat allows a
network adminis1rator to:
• Set up and manage users and devices on the netwcrk
• Monhor use of 1he network
• Fix problems
• Distribtr.e softvvare.
Network servers
A network server is a oombinatlon of hardware and software. Its job is
to provide a service to a network and hs users. Examples of network
servers are:
• Network server Manages all the data being sent across the network
to ensure it reaches the right users.
• File server Manages how files are saved and relrieved to and from
networked disk drives.
• Print server Provides printing services across the network.
Network protocols
A protocol is a set of rules that tell us how an activity will take place.
Network protocols are ,he rules that determine how data will be shared
ae<oss networks. If a manufacturer of hardware or software makes sure
their product abides by the agreed network protocols then it will work
wi!h other hardware and software on that network. The mos1 important
protocols are:
• Ethernet The set of rules that slate how network hardware is joir,ed
together with cables.
• Transmission Control Protocol / Internet Protocol (TCP/ IP) The
rules that state how data Is sent between network hardware devices
along cables.
, ACTIVITY
I
\/Vrite a report about the main
types of network hardware
described in this section.
Investigate your school network
and Illustrate your report with
pictvres taken o' your school
network equipment. If you have
time, include an outline plan of
your school Indicating where 1he
main netvvork hardware is.
The internet
LEARNING OUTCOMES
In 2.3, you will learn about the
'acilities and services available on
the Internet.
The internet
The internet is a global network of computers. It is not run or controlled
by anyone. It is made possible becavse there are agreed protocols that
all cornpulers can use.
There are smaller 'internet-like' systems.
• An intranet is a small private network tnat looks quite a lot like
the internet but is only available to people working for a single
organisation.
KEY TERMS
Internet The lntei'T'et Is a global
• An extranet is an intranet that makes some information available to
people oulside tne organisation. such as customers or suppliers.
network of computers. II is -iot
11.ln er controlled by anyone.
Protocol A comrnunlca11ons
protocol ls an agreed set of
r-,les and signals that control
how signals are sent. If two
computers ere using the sar,e
protocols then tney can snare
informalion.
I
The first webstte was created In 1991. By 2018 fne number of
websttes had grown from one to more than 1.5 billion.
By 2018 Google was processing 40,000 searCi'.es a second. Thal is
3.5 billion searches in a day and 1.2 1rilli0<1 ln a year.
File transfer
The internet is based on the transfer of files of information between
compUiers.
• When you upload a file you put it on to a computer system that ls
connected to tne irnernet so tnat other people can access it.
• When you download a file you copy it on to your own computer from
the internet.
Protocols
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to =e.
A communications protocol ls an agreed set of rules and signals that
control how signals are sent. If two compU1ers are using the same
pro:ocols they can share information.
• File Transfer Protocol or FTP is 1he protocol used to allow computers
to upload and download files.
• Telnet was a protocol used in the early days of the Internet. Compared
to modem systems it is more vulnerable to security problems.
• VoIP (Voice over lnterne! Protocol} is a protocol tha1 allows you to send
phone messages over the Internet instead of by phone lines.
• HTTP {Hypertext Transfer Protocol} is the protocol used lo allow
computers to share web pages. II oon1rols 1he comm,mica1ions
between computers.
The World W ide Web (WWW)
•• •
MoSl of the communication on the internet Is through websites.
The collection of all the websites in the world is called the World
Wide\l\leb.
Internet vs World Wide \l\leb
• A web page is a document set up In a form suitable for people all over
the world to view tt.
• A website is a collection of web pages made available by a person or
organisation.
• A hyperlink is a link from one web resource 10 another related
resource. Tne related resource may be in the same webstte or in
another website.
• A URL (Unttorm Resource Locator/ is tile web address of a web page.
• A webserver is a computer connected to 1he internet that holds one or
more websites for people to acoess.
• A web browser is a pieoe of software that connects to a web page and
displays it on your screen so you can view it.
• HTML (Hypertext Markup Language) is the language used to control
how a web page appears on your screen. II uses tags such as <b>
(for bold text}, which all web browsers can understand and display.
Online communication
The internet enables a wide range of different types of oommunicalion.
Fer example:
• Newsgroups and discussion forums are web services that accept and
display messages on a particular subject of interest. Typically anyone
can send a message, by web link or email, and all the messages can
be read by anyone who is a member of the group or forum.
• !RC (Internet Relay Chat) allows real-time web discussion. Messages
are displayed immediately as you type them in. !RC is sometimes
called instant messaging. It is mere Informal and interactive than
newsgroups.
• Blogging (web logging) is where users snare lociger personal
messages, somewhat like diary entries, on a website. Other users can
read and comment.
• Vlogging is video blogging. As wtth a blog, users reoord personal
stories and sriare them on video-hosting sites. Other users can then
watch and comment.
• Podcasling is similar to blogging, but Instead of text content, audio
or video content is provided. People might listen to these online, or
download on to tablet computer or smartphone.
Online communication technology is often called social media.
Companies suoh as Facebook and Twttter offer tools 10 allow people 10
communicate with friends and others ,,rno have similar interests.
r,MM/\/J
The terms ln:emet and Wl\11/1/ are
often confused and used to mean
the same U,lng. They are different,
Tne internet is all the networking
equipme.~t a,,d communicaticYl
technology toat allows us to
communicate and find Information
online.
The WWW is the information that
is available on all of !he websttes
across the world.
••
A 'search engine' sucn ~ Google
keeps indexed records of all the
web pages tnat can be accessed
via hot links, When you type in a
search word, Google gives you a
list of links 10 all the Web pages
that oontaira that word.
ACTIVITY
A lot of different prolocols and
oommunications systems are
mentioned on this page. Pick
any three of lhese and carry out
your own full investigation. Wrtte
a report on each of your chosen
themes.
LINK
Find out more about
Misuse of the Internet by
criminals: 3.2
How compulers help with
problems, Including e-learning
and e-commerce: 3.4
<'-o
Mobile communication
networks
LEARNING OUTCOMES
In 2.4, you will learn about the
role o' mobile communlcalion
networks ,n providing 'any1ime,
anywhere' acc;ess to ne.works
H is predicted that by 2020 there will be 4.75 billion mobile phone users
In the world. Modern mobile phones are also known as smartpnones.
Smartphones do much more than allow us l o make phone calls. \lo/e can
use them to send text and multimedia messages, to make video calls, to
play games with friends and to browse the internet.
This is all made possible by mobile communication networks. To access
voice and data services , a mobile phone must be connected to a mobile
communication ne1Work.
Mobile communications netvvorks were introduced in the 1980s :o allow
people to make calls on the move using mobile pnones. Since then, data
networks, Including the internet. have become more important to us.
Mobile nelwork verSIO'lS are given
a code made tJP of the version
number and 1he letter 'G'; 4G
for example. The G stands for
generation.
Over 1ime, new versions, or generations, of mobile communication
networks have been imroduced to allow data and internet access.
Generations of mobile communication
1G The first generation cf mobile networks was meant only for mobile
1elephone communication. The network was slow and could not be used
for data.
• • ! • •
2G was introduced In 1991 and was 30 times faster than 1G. The second
genera1ion of network could be used for text messaging as well as voice.
3G By the early 2000s, \NVVVV was developing into a multtmedia service.
3G provided faster data speeds that allowed users to access 1he inteme1
and to send pictures and video as well as text. The 3G netvvork is more
secure than earlier generations.
4G The main advantage of 4G is the speed at which tt operates.
Broadband download speeds mean the service can be used for
applications such as viewing video and 3D gaming. Better security allows
safer use of services such as Internet banking and snopping.
5G was Introduced in 2018. It can be up to 1000 times faster 1han 4G,
allowing a full HD movie to be downloaded in around 10 seconds.
Figure 2.4.1
A typ,cal 20 moo e pnone
How have mobile networks changed?
New generations of mobile oommunioation network have changed t11e
way we use our mobile phones.
• We are conslantly connected to tr,e internet, receiving emails and
messages as they are sent.
• \/Ve have aocess to multimedia seNices that allow us to stream music
and video to our phones.
• There are new ways 10 communicate with video, Instant messaging
and email available as well as voice.
• SeNices are available 'anytime, anywhere'.
• Links to Global Positioning Systems (GPS) provide seNices that are
,elevant to the area a person is using the phone from.
• More powerful smartphones and tablets provide access to software
applications.
As smartphones and tablets have become more powerful and use larger
full-colour screens, battery life has become a problem for many users.
Uses for mobile computing
In the work plac,e Employees in remote locations have access to the
same up-to-date information that they have in the workplace. Tney can
stay in touch with colleagues 'anytime, anywhere' by phone, email,
Instant messaging or video link.
In education Students have access to learning materials 24 hours a
day. The learning materials they access can be multimedia, not just primbased. Students oan use video and lns1ant messaging to collaborate
wtth teachers, other students and subject experts wherever they are.
In commerce \/Ve can shop and use banking and other services from
any looation at any time. GPS services can give information on where to
find local services and shops.
For leisure \Ne can acoess entertainment and gaming as we move
around. \Ne can stay in touch with family and friends through messaging
and video link and make new friends, wherever tney may live.
Mobile communication networks have changed the way that we use
technology. Wnerever there is a mobile network link available, interne'.
services are available. Mobile networks have become a common carrier,
available to everyone, anywhere.
ACTIVITY
Research the internet to find a
picture and specification for a
typical 2G mobile phone. \Nrite
a report that describes the
di'ference between 2G phones
and modern smartphones.
Include input, output, storage
and data speeds. What can
modern smartphones do that old
2G phones could not?
SECTION 1: Multiple-choice questions
1 An area where wireless access or ,eceptior is
available Is called:
a ho1spot
b Internet ca'e
c extra1e1
2 When dala communication occurs in bo,h
directions at the same time the 1ransmission
mode Is called:
a half duplex
c
simplex
duple)(
b To guard against viruses
c To ser>d email across the in1ernet
8 What is used 10 provide a wireless connection in
a local area network?
a Fibre-optic cable
b Wireless Access Poin1
c Wide Area Network
d Hub
9 What kind of network ccnnects computers
d complex
withln 1he same building (for example, a scroo9?
3 Which type of cabling uses light instead Of
electrical pulses to transmit da!a?
a Intranet
b Bluetooih
c Wireless
d F1bre-op1ic
4 \/Vhich of the following Is an example
a To connect a device to a network
d To crea1e web pages
d line of sight
b
7 What is HTML used for?
a Tre internet
b Wide Area Network
C Local Area Ne~NOrk
d Metropolttan Area Network
1o \f\lhat does '.he G stand for In 4G?
o: a
network protocol?
a Router
b 1Nlreless Access Point
c Webserver
a
Generation
b Gigabyte
C
Google
d
Guestuser
d Etnerne1
5 \f\lhat ne1worl< device is used to join a local area
ne:work 1o the in1ernet?
a Hub
b Router
c
Server
d Switch
6 What nelwork device converts ne1work darn
into a format 1ha: can be sent across a public
telephOne system?
a Modem
b Switch
c Smanphone
d Bridge
Further practice ques!ions
and examples can be found at
www.oxfordsecondary.
com/9780198437215
SECTION 2: Structured questions
1 Fill the blanks witn the appropriate words given
in the box below
web server, web page
website, web browser. URL
a A _ _ _ _ _ _ displays a web page so
b
tt,at a person can read it.
Every web page has its own address called
3 Explain how modern mobile communication
networ1<s can benefit:
a a student stuclying at school
b an engineer wno services and repairs
equipment on customers premises.
4 What is a r etwork proiocol? Give two examples
wtth a brief example of their purpose.
a _ _ _ _ __
c
A website contains many
_ _ _ _ _ _ S,
d A website Is stored and accessed from a
e
A _ _ _ _ _ _ ls a collection of web
pages owned by a person or organisation .
2 Brie~y explain the role of each of the network
h;;irdware devices listed below
a Hub
b
Svvll ch
c
Modem
Network interface card
d
Further practice questions
and examples can be found at
VN{w.oxfordsecondary.
com/9780198437215
The impact of technology
LEARNING OUTCOMES
In 3.1, you will learn how
i~formallo'l technology Is
changing our lives, sometimes 1n
a positive way and sometimes 1n
difficult and cr.allenglng ways.
Information technology has changed our lives. It has had an impact on:
• the way we work
• the way we learn
• how we buy things
• how we interact with governments
• how we keep in toucn with our friends
• how we spend our leisure time.
Overall, tne impact ol IT has been positive. Scme of tr e changes IT has
brought nave been difficult and challenging for society.
KEY POINTS
Phishing is a method of
committing fra.d onllne wne!'ll
many Ihousands of people are
contacted i'l the hope ot catching
one or two v1ctlms.
Cyber bullying Involves using
social media and mobile phones
to commit bullying. The bully
usually remains ar.onymous.
In 2017. Twi'..er claimed 328
million actiVe users.
In 2018, Facebook claimed 2.1g
billion ac1ive users per mo"lth.
Social media
Social media is a name given to websites lilat provide ways for people
to communicate witn each other and In groups. Groups o' people with
a common interest can use social media to work toge:her informally,
sharing experiences and expertise.
Some of the most popular social media sites are Facebook, liNitter,
Linkedln and YouTube. Some, like Tvvitter and Facebook, offer general
tools and members decide how they will be used. Some sites have a
focus. Linkedln focuses on tile world of work, for example. Oiher sries,
suon as YouTube that publishes mainly video clips, favour a technology.
Social media has many benefits. Ii helps people develop new
friendships. It supports people in learning and sharing expertise. Some
people have used tt to build new businesses and careers that could nol
have existed without social media.
There are also dangers in social media. Some people have used social
media to commit fraud. A criminal has aocess to millions of people and
even the most unlikely fraud will catch someone in its nel. A criminal can
use people's personal data to mask fraudulent requests so that people
think they are legitimate. Unsuspecting persons may divulge personal
Information such as their credit card details or passwords. This is called
phishing.
Cyberbullying is also a serious problem for many you'lQ people.
Cyberbullying Is a deliberate and repeated form of online harassment.
Bullies use social media and smartphones to make persistent threats
that the victim finds tt hard to avoid.
Figure 3.1.1
The Faceoook and Twitter
logos
The beneftts of social networking do not reach everyone. In the poorest
parts of the world, people do not have access to networks or 1he
equipment lo benefit from social media.
Crime and punishment
Police forces across tne world use technology in their fight against crime.
DNA testing has come about through technology a'1d helps police solve
crimes. Powerful dalabases are used to help solve crimes and surveillance
1echnology helps preven1crime in the first place.
Criminals have developed new crimes 1hat depend on technology.
Cybercrime is a 1erm for crime carried out usir.g computers and the
ln1ernet. Cybercrime usually involves criminals hacking into systems to
steal money or commi1 fraud. 11 can also involve selling and distributing
Illegal goods such as arms, dn;gs and obscene ma1erials.
Some criminals use ,he lnterne110 attack commercial and government
websites . They aim :o disrupt and even make it impossible to use the
website. This is called a denial of service attack and can be very harmful
10 an organisation and Its customers.
Government
Governments use technology to help 1hem run 1heir counlry. Technology
allows a government 10 collect information on i1s economy, businesses,
1ransport, housing and people.
Once collected, the da1a can be processed and used to make decisions
on how the country should be run. Some people worry about the
amount of information 1hal governments s1ore about individuals and how
lhat information can be used.
Work and jobs
\Nork is a major area where technology has had an Impact on people.
Automation has replaced many manual jobs, while o1her new jobs
have been crealed. The ln1ernet means tha1 work can be done from
anywnere. with more people working from home.
Some people have benefitted from the grow1h of Information Technology.
They may work In interesting and well-paid jobs In new areas, such as
computer gaming. 01tlllrs see their jobs under threat as automation
and robotics are introduced in traditional indus1ries, such as car
manufacturing.
ACTIVITY
Research news sites to find a
current article about tne impacl of
technology. Choose a s1ory tha1
interests you. It might be about
robolics, cybercrime, science or
social media. INrite a brief report
thal summarises the s,ory. Make
a list of fne benefits and costs of
technology you 1hink 1ne story
highlighls.
Misuse of data
LEARNING OUTCOMES
Comp.Jter comm,.mlcations and
precesses are more powerful
than ever before "his Is good
for us al - a g:ves us new tools
10 do our wo'k. But n also
brings dangers. In 3.2, you will
learn aoou1 '.he dangers that
m ght arise from misuse of data,
lnolJdlng compu1er crime.
Privacy and security
Computer networks and the internet allow us to share all sorts of
information wtth our friends, and 1Ni1h t11e whole world. This brings us
many advantages. But tt also brings risks to our pr~1acy and the security
of our informalion.
• Privacy: The biggest risk to privacy is that people are careless. Some
young people put private information up on biogs or message boards,
not realising tna1 everyone - their parents, their teachers and all their
friends - can read tt. ff is your responsibility to be careful about what
you share with others.
• Electronic eavesdropping: Even if data are protected by passwords
and other methods, some people will make efforts to read other
people's private information. The biggest risk is for celebrities, bu1
we should all be careful about our passwords. Don't tell anyone your
passwords.
• Espionage: Espionage means 'spying'. Industrial espionage is spying
on businesses. We have all seen In the news that information can be
leaked from pollticians, from businesses and from the military. The
internet can make it easy to share this Information wtth people all over
the world.
• Sur:veilla.' lce: Electronic means can be used to monitor people's
activities. Governments can use electronic systems such as CCTV to
keep an eye on activity in the streets, and they might monitor email
content and other communications. Different governments throughout
the world have dttferent attitudes to sur:velllance.
Bias and persuasion
••
An International i,ur:vey found that
many young people think !hat .i
Google searCil only brings up true
resutts.
This is wrong - Google just
searches for words that rnalch
your search terms - tt does
not guaran:ee !Pat what ~ finds
is true.
Almost everyone in the world has a point of view. People feel strongly
about many things: polttics, science, national inlereS1s and beliefs. This
will affect what they say on their websrte.
• Propaganda ls when a government (er other organisa1ion) puts
out a biased viewpoint on purpose to persuade people of a point
of view.
• Bias Is wr.en a person's point of view affects 1•/nat !hey say, or how
they say It. It might no1 be deliberate.
When you read a website, try to remember that the source migh1 be
biased. Some news sources nave a good reputation for unbiased
reporting - these are good sources of information.
Illegal copying and computer fraud
New lechnology makes it easy to copy elec1ronic Items such as music,
games arid movies. The risk is that the people who wor1<ed hard lo
create these wor1<s miss out on earning any money from them, because
people make copies without paying.
Software piracy is a particular form of illegal copying. Some people make
copies o' expensive computer software and sell them illegally.
Fraud is a general term for any Illegal deception or Irick. Comptrters can
be used to commit fraud and swindle money from people.
• lden1ity theft is wnen a criminal pretends to be another person. By
s1ealing someone's identity, the criminal might be able to take money
from their bank accoum.
• Credit card fraud is a form of identity theft where a criminal uses
another person's credit card to buy goods or illegally access cash.
EXAM TIP
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stuol/j, because /jDU ca,,._,
ofte"" Yelate what /jOu
~ave l~aYv.eol to l•veltJ
,te"1,l,S '"" ti-le ""fWS, OY • .,.,
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~I-le co..-...ect ter¾<.5 to use
'"" oroley to get ""'-ax•""'-u"""
eKl'I I¾ l¾a ,-ks .
Computer misuse: counter measures
There are measures that organisations take to protect against misuse of
dala. These are called counter measures.
Physical security ensures that lmportan1 parts of the system such as
netvvork servers and network data storage drives are protected behind
locked doors. Key codes and biometric sys1ems are used to make
unauthorised access to systems more difficult.
Intrusion detection systems warn wnen there has been unauthorised
access 10 a system so 1hat action can be taken.
Back up and recovery systems store versions o' data held on a
system at regular intervals so data can be recovered if they are lost
or corrupted.
A firewall is combined hardware and sofu'llare that prevents
unauthorised access lo a computer network.
Anti-virus software prevents damage from viruses and other malware
affecting data. Anti-virus software must be updated regularly to be
effective.
Data encryption is a method of coding data when they are sent
across the imernet. Encryption prevents dala being read even if they are
ln1ercepted by a criminal.
/ ACTIVITY ~
Many young people have
mistaken beliefs about the
internet
• They might think 1hat websites
they find through Google are
always accurate.
• They might not realise how
risky it Is to share personal
Information onllne.
lmag ne you have been asked
to write an article for a :eenage
magazine, exolain ng to young
people why they need 10 be
careful when reading websites or
upload ng personal information.
Wri!e a lively article explaining
some of the real-life risks for
young people.
-
Individual working practices The way people use a computer system
Is important in fighting the misuse of data. Individuals should set strong
passwords and never reveal them to otners.
People should be careful not to open suspicious-looking emails.
Using memory sticks 10 transfer data to and from 1ne system is often
discouraged. A memory stick can introduce a virus or easily be lost
along with the sensitive data it may contain.
LINK
Find out more about
Reliability of onllne informa,lon
1 .13
The lnlemet: 2.3
Computer security: 3.3
%
Computer security
LEARNING OUTCOMES
You learned about 1he mls..,se of
c!a1a aPd computer crime
in 3.2. These are not :he only
rlsks when using a computer.
In 3.3, you will learn about 1"e
ways 1rat people seek lo deal
with cor,pvter risks and Improve
computer security.
Physical access
Some organisa!ions deal with computer security by preventing people
from accessing computer equipment. At its simplest, they can use
locked doors, security guards and security passes.
Biometric systems are computer systems ihat identify a person by their
boc!ily features. The two mos! common types are fingerprint readers
and iris scanners. There is a pictt.>re of a fingerprint reader in 1.6.
Figure 3.3.1 shows an iris
scanner. tt scans your eyes with
a (safe) light beam, 10 read it a
bit like a fingerprint. Biometrics
is a high-tech way of controlling
access to a high security
building or room. It means
people don't have to carry a
security card that mignt get lost
or stolen.
Disaster recovery
Disasters such as hurricanes or major cyber attacks can damage
computer equipment or data. Even on a small scale, your computer
could get dropped and damaged - that could be a disaster for you. How
can computer information be protecled against disaster?
• A backup is a copy of all yo..,r data, stored away from your computer
in a safe place. If there is any kind of disaster, and your data are lost,
you can turn to your backup. Bringing back data from backup is called
recovery.
• Backups should be stored somewhere safe from c!isas!er, in a
separate place from the computer. Many companies use a fireproof
safe or a waterproof safe to store backup disks. Individuals can store
backup files using cloud storage.
• Archiving is keeping copies oi data that are no longer in use. At some time
in the future you might want to see your old irr.ormation again.
Software security
As well as physical security, there are software features and applica1ions
1ha1 help with computer security.
• Passwords are a very common feature of compvcer systems. Typically,
you log in using a user ID (identity) that is public and a password that is
private. Do you log In to a scnool networl< In this way? Why is it a bad
idea to use an obvious passvvord, like your birth date?
• Encryption Is a way of putting data into a secret code so thal !hey
cannot be read unless you know the code. An algorithm is used to
encrypi 1he information.
• Virus protection: a computer virus Is a destructive piece of software
thal some users accidentally copy on lo their computer syslems. A
computer virus can cause loss of data or send seCfet information,
such as your credtt details, to a criminal. There are software packages
such as Norton Security lhat find viruses and prevent them from
harming ycur computer.
• Viruses can also be avoided by making sure you don't copy software
and files from unre'iable sources on to you' compu1er system.
• A firewall is a softvvare system that blocks off communica1ion to a
network from computers outside 1he nelwork. For example, a firewall
is used to prevent people on the lmernet from connecting to a private
Intranet. The firewall will usually !el some communications through,
such as emails from irusted sources.
Virus and malware protection
KEY TERMS
Data security means keeping
daia sa'e. It also means making
sure data are kept private and
not read wi'.hout perMlssion.
Data integrity means making
sure 1hat data are nol spoiled,
changed or deleted.
Backup A backup Is a copy of
ail your data, stored away from
your computer In a safe place.
I' 11'.ere Is any Ki'id of disaster,
and your da:a are los1, you can
turn 1o your backup. Brlnglng
back data •rom backup Is called
recovery.
Malware. short for mallcio1.1s software. is designed lo do harm to your
compUler syslem and the data stored on it. There are many types of
malware including viruses, which can Infect and damage data and
program files.
Organisations and individuals install anti-virus software to prolect againsl
malware. II is important to keep anti-virus software up-to-date as nevv
malware is being developed all the time.
Secure working practices
Security can be improved by the way ihat people work with computers.
Password protection is far more effective tt individuals use strong
passwords that they change regularly. You should never reveal
your password to anyone or allow them to use your account or
security cards.
Organisations have strict rules about what data can be stored on mobile
devices such as laptops. A lap1op can be losl er stolen along with all tl1e
dala stored on it. 11 is safer i o save sensitive data on network drives er
on cloud storage.
Individuals can protect against malware and viruses through the way
lhey work. Emails and attacnments from unknown sources should
never be opened. Care should be taken 'Nhen browsing the inlemet.
Un1rusted sites can pose a risk. Transferring files using flash memory can
lead to loss of data if a memory slick is lost , but also risks viruses being
inlroduced to a compUler system .
, ACTIVITY
I
Carry out your own research and
write a short report on each of
these:
• blome:ric systems
• firewalls
• computer viruses
• open source software.
.I
UNK
Find out more about
Source code: 8.3
Misuse of dala: 3.2
0~
Practical applications
LEARNING OUTCOMES
Computers are used In a wide
range of jobs and IPdustries to
help with work They are used to
solve real-life problems. 1° 3.4,
you will learn aboU11he lmpaci IT
has had In business and society.
Education
Teachets and students in crdinary classrooms make use of computer
technology to support learning activities; for example, the use cl t11e
ln1etnet to help wtth research projects. Students can also use video and
audio technology 10 present their work.
E-learning is changing the way that people learn. It allows people tc learn
anywhere and at any time - not just in the classroom. E-learning uses
the internet to provide access to learning materials, tutors and experts.
Learning matetials are ofte11 Interactive and Include video, audio and
animations as well as traditional text. The Internet can be used to allow
people in different cities or countries 10 learn togethe<. For example,
video conferencing can be used 10 allow an expert to join in a class from
another location.
Some a-learning courses are studied entirely online. These can be useful
fer people living In remote locations, sucn as small islands.
Commerce
The way that things are bought and sold is changing because of
information technology. Electronic Point of Sale (EPOS) systems are
common. Bar codes printed on goods are scanned and the bill for
1he goods is presemed to the customet. The information oollectect by the
EPOS scanner Is used to order replacement items for the shop. The
Information can also be usect to provicte ctala on the shopping habits
of customers. Shops use this information to senct special offers to
customers.
Mos1 large retailers now have an internet site where people can ordet
goccts online and have them cteliverect ctirectly to their homes. Other
retailers only sell their goocts online and have nc physical shops at
all. In some cities. high street stores are closing because people are
choosing to buy more goocts online. CompU1er systems provide tracking
Information so tnat the retailer and customer know when orcters will be
delivered.
Law enforcem ent
You have learned in 3.3 about biometric systems such as fingerprint
readers. Police forces make use of specialist input devices to record
faces, fingerprints anct DNA. The software will then mateh these wrth
electronic records stored on tne computer system.
Electronic communications help police forces in different countries to
share information and coordinate their activities.
The police also make use of technology to monnor traffic. Scanning
devices can be usect to read number plates automatically anct to
measure the speed of cars.
Manufacturing
Many industries depend on compu1ers lo conlrol processes. For
example. a furnace or a cold slore will have to be kept at the righl
1emperature. Compu1erised systems can be used to monitor
environments and industrial syslems .
More complex activities such as assembly and welding of parts can be
carried out by robots. In the past, people Imagined 1hat rcbols would
be like metal men. In real life 1hey are simply moving machines that can
carry out repelitive tasks very quickly and precisely, wtthout getting 1ired.
Science
Scientists also make use of computer monttorlng. In experiments tt is
often important to keep 1rack of ccnditions - examples might be 1he pH
(acidily) of a solution or the position of a glacier. Accurate readings have
10 be taken regularly, over long periods of time. Rather than a labcralory
assistant taking readings, condttlons can be monitored directly by
computerised sensors.
Some scien1ific study depends on exploration of dangercus or extreme
places. An example might be the lava field of a volcano, or an asteroid
in space. Robo1 monitors can go to places where it would be :co
dange.-ovs or expensive to setid a person.
Leisure
The way we spend our leisure l ime has been changed by technology.
Digital 1V and music systems stream films and ml>Slc inlo millions of
homes on demand. People have far more choice about what they watch
and listen to, and when.
Games make use of specialist peripherals to give 1he player a more
realistic experience of the action of 1he game. Many recent games have
hand-held remote devices that detect movement. Sy holding this device
you can simulale action sports, such as playing tennis.
Music editing systems allow the user to record audio tracks and
store them in the computer's memory as digttal audio. Then they can
manipulal e the music to mix multiple tracks and apply sound effecls or
filters.
Medicine
Many specialisl systems are used in hospitals. Here are some examples.
• CT scan: 1his is short for X-ray CompUled Tomography. It uses
computer power to generate a three-dimensional image of the inside
of the body by merging multiple X-ray Images.
• MRI scan: 1his is sriort for Magnetic Resonance Imaging. This uses
magnetism to produce a delailed Image of body !Issues thal cannot be
picked up in X-rays.
• E.xperl systems: these are complex software models that use stored
Information to provide answers 10 problems. In medicine this software
ls sometimes used to help with diagnosis of Illnesses.
/ ACTIVITY
Cnoose an area of work where
computers are used 10 solve
problems and bring benefits.
Wme a report on all the uses of
computers in tnis area of work.
LINK
C''O
Find out more about
How compUlers affect tne way
we work: 3.6
New jobs In 1echnology: 3.7
Impact of emerging
technologies
LEARNING OUTCOMES
New technologies 1hat will
change 1he way we use
complJlers are emerging ail 1he
lime. In 3.5, you will learn abol.11
some of ,he most lrnportarn
recem developmer,:s.
Expert systems
In 3.4, you learned that expert systems are used in medicine. An
expert system is a complex type of soflv\lare used to answer questions.
Typically, expert systems are used for diagnostics. 'Diagnostics' means
finding out the cause of a problem.
So, In medicine, you might enter a patien1's symptoms Into ,he
computer. The expert software will compare these symptoms with its
records of different diseases and find out which is the best match.
Expert systems are also used to diagnose problems in car seNiclng and
computer maintenance.
Techno'ogy 1s cilang ng the way
we use cars to 1rave1. Driver error ,5
by far the biggest cause of motor
accidents, Car marn.ifacturers are
using technology to reduce the r.sk
of d·ver error,
Automated cars use sensors to
build a picture of the world around
:hem. Artif,cial Intelligence (Al)
systems make sense of w'nat is
happenlrg around tne car. Coritrol
systems ravigate ,he car in
response to lnstrucliors Fro'll 1he Al
systems.
Assisted driving systems are
now common In cars, A human s
In control of the car blJI in extreme
circumstances automate systems
take over. For example, if sensors
on the ca· detect a crash liazard
the brakes are apol ed.
Semi-autonomous vehicles
are being p loted on roads aroJrd
1he world. In normal condit,ons, a
se'Tli-autonomous car drNes liSe~
When a hazard s detected, signa s
are sent to the driver to take back
control
Fully autonomous vehicles w ii
dnve tr.err,5elves wthout the need
for any human control. These
vehic'BS are expected to be in use
by 2025. They may be used in
special lanes on ma.or roads before
'.hen
Robots
In 3.4, you learned that robots are used in factories where repelitive
1asks must be carried out. Robots work quickly and accurately. They use
sensors to measure treir environment, and computer-controlled motors
to make actions.
CADD
Computer-aided design and drafting (CADD) is tne use of computers
to create designs for engineering and manufacturing and the plans for
buildings. It is easy to revise, make changes to and test 1he strength
and suitablltty of the design. Modern CADD packages allow rotation in
1hree dimensions, so you can look at the planned object from any angle.
CADD is also used to produce computer animation for special effects in
movies.
CAM
Computer-aided manufacturing (CAM) is the use of compuler software
to con1roi the machines and tools to manufaOiure objects. Often CADD
and CAM go together. so you can design an object on the screen of the
compUter and '.hen send the ins:rvctions to a machine that will cut the
object from a piece o! metal.
CAE
CADD, CAM and other processes, such as planning, analysis and
simulated testing, all combine 10 create a new modern industry called
'Computer-aided engineering' (CAE). It is much cheaper 10 test out
designs on the computer, ra!her than in real life. For example, a new
bridge design will be planned and thoroughly tested on the computer
syslem before the design is approved to build a real bridge.
Artificial Intelligence
Al aims to create machines that can mimic lhe way lhat humans solve
problems and carry out lasks. Al systems look at the world around them
using a range o' sensors to detect llgh1. movement, heat and so on.
Computer scientists and researchers are developing computer programs
lhat can process thal information quickly and use it to make decisions.
Comrol systems are used to lurn those decisions inlo actions. To fully
replace human actions, Al machines will need lo learn from miSlakes and
successes. They will also need lo think ahead tc plan for situations they
haven' t yet dealt with.
Al systems are being developed to drive cars and to pertorm medical
diagnoses. Tney are also used for milttary purposes: to track and guide
weapons, ior example.
Cloud computing
Cloud computing is a modern use of internet technology to carry out
your computing work. Instead ol using software and files stored on
your own oomp.,1er, you use large capacity computers owned by
large organisations such as Google er Yahoo. Of course, you still need
a computer ol your own to connect 10 the inlernet, but most of the
software and dala is stored somewhere far away.
This has several advantages: it oan be a cheap solution, it can be good
for people with small computer syslems without much personal storage
capacity, and it means you can connect to your files from any computer,
anywr.ere, so long as it has an Internet link. An example of a cloud
computing software application is Google Docs.
Wearable technology
'Wearable technology' is clothing lhat has computer systems built inlo
it. It could be used for a serious purpose - for example, to monitor the
blood pressure of an ill person or to track the speed of an athlete. It can
also be used for fun - for example, to create a T-shirt with a moving light
show on it.
ACTIVITY
Research real-life applications of
me technologies mentioned on
this page.
Smart objects
A 'smart object' is any object that sends out wireless signals thal can
be picked up by local computer systems. Some smart objects also have
lheir own processors inside them. At present this leohnology is mainly
used lo help you 10 find and track objects, for instance In a warehouse. It
is also used for secortty systems - for example, lo monitor security tags.
LINK
Find out more about
Web cams: 1.6
C''b
The world of work
LEARNING OUTCOMES
Computers rave affected ,he
way we work nowadays. In 3. 7,
you will find out about new jobs
that have emerged wttn new
computer 1echnology. In 3.6, you
will see how comp-,ters
have ch?nged work pq.nerns and
affected the way we work.
Computers in the office
At one time, all office documents were fyped up on typewrtters. It was hard
10 make corrections and changes. Copies were made with a photocop:er,
and documents were sent by post or by fax. Nowadays, all of tris Is done
wrth word processing and email. The ideal is a 'paperless office' where a I
dociJments are stored electronica ly en the computer - saving space and
priming costs and reducing env·ronmental impact. Most offices sbll have
some paper documents, though.
Computers at school
Not all schools have computer equipment. But where computers are
available in school, they can help to make learning easier - if they are
used properly. Tnere are two main ways that computers can be used
at school:
• to help young people to develop better computer skills, so they can
get modern jobs
• to use computers lo support learning in other subjects - for example,
writing essays, doing research, making graphs, and so on.
M edia, news and entertainment
Television, radio shows, newspapers, magazines and movies all depend
on computer technology, Reporters send in stories using computer
communicalions, publishers prepare layout and designs using softv,,are,
and special effects in sound and vision are made using computer
sySiems.
Electronic publishing is a lower cost way 10 create magazines and books
tha1 can be read over 1he internet rather than on paper.
Electron.c readers (a-readers) are hand-held devices tnat !el you read
books and newspapers. One small device can ho'.d thousands of books.
Loss of jobs
Many people are oonce'Ped that Jobs w;II d saopear. For examp e, a car
factory might have employed hundreds of workers, but now employs fa•
fewer people because much of the work s done by robots.
However, the hope is that new Jobs will become available, for those
wilh computer skills, and that if the routine jobs are increasingly
compU1erised, people will be free to spend time on other tasks ,hat are
more varied and interesting.
There will always be jobs that cannot be completely oomputerised.
Examples include the job of a policeman or a nurse, a tour guide or
an athlete.
Retraining
You have seen that computers in schools will help young people 10
develop computer skills. Older people might need training later in
ltte - there were no computers when they were at school. As old Jobs
disappear or change, there is a need for new s~lls.
There are online oourses !Pat can help people to develop compU1er
skills. Olher people will learn on the job, adapting to new ways o'
wor1<lng that involve techf1.()logy.
A ~ Udy in lhe USA es;imated
that 50% of jobs are oompatible
with teleworking and 85% of
Americans say 1hey would hke lo
telework 'or part of the week, but
only 26% actually do.
Telecommuting
In many parts of the world, people have to travel long distances to their
jobs. Roads become very crowded. Traffic causes pollution and fuel
is expensive. Travelling to work is called commuting. An alternative is
telecommuting. Tnis means that people work from home using oomputer
communications. This is not possible with all jobs. and in most cases
people only 'teleoommute' for some days and travel into the office for
others. Telecommuting also provides a way of wo~ng when there are
disasters or bad weather tna1 stop people from being able to travel.
LINK
' ACTIVITY
How are computers used In your school?
Visit a workplace - pemaps where a parent or an older sibling works
- and find out about how they use computers.
%
Find out more about
Using computers to solve wor1<
problems: 3 ..!.
New jobs in technology: 3.7
••
Jobs in technology
LEARNING OUTCOMES
There are ma"}' Jobs available
lhat are conoerned wtth
designing and runrii'1g CQmputer
systems. In 3.7, you will learn
some1h,ng about the jobs tna'.
have been crealed by tt,e growth
In the use of comput8fs.
Programmers
In Untt 8, you will learn about how CQmputer software is created by
programmers. Nowadays, most computer software is created by large
1eams of programmers. Some of the jobs involved in programming
include the following.
• Applications and games programmers create commercial software
that performs useful functions for customers.
• Systems programmers create sy5lems software (see 1.8) thal helps
the computer sy5lem to funclion.
• Software engineers are senior programmers. Many people feel tt
is Important to give programming a professional status. and lhe
responsibilities that go with tt. The lerm does not have an agreed
definriion.
• Web developers are software developers who work developing World
Wide Web applications, such as websites and web services.
• Software testers work wtthin tne programming team, carrying out tests
and locating bugs and errors In lhe code. See more about testing
in 7 13.
Systems analysts and designers
Sy5lems analysts and designers have the job of designing and planning
software solutions. They typically visit an organisation lo see how
computer systems can help with lhe work, and plan out !he software
lhat '.he organisalion will need.
Administrators
A Systems Administrator (often called SysAdmin) has the job of
supporting and running the computer system once tt has been
lns'.alled and is in use. They mighl have the responsibiltty of helpi,ig
lheir colleagues to vse the system, fixing problems and making small
amendments lo software.
In a larger company 1he work of the SysAdmin might be divided among
several people.
• A database adminislrator (OBA) maintains a dalabase of information.
He or she Is responsible for making sure the data thal are stored are
accurale and accessible to users.
• A network administra1or maintains a computer ne1work (LAN) including
bo1h the hardware and the software that makes the system work.
• A file librarian has the very specfflc job of keeping track of all the flies
that are needed within an organisation and for organising backups and
restoring files that are lost or damaged.
• A webmaster or website administra1or is a person responsible for
main1alning a website. They have to make sure that the hardware and
software are operating accurately, make corrections and changes,
,espond 10 questions frcm users and check 1he traffic through the site.
• The most senior of 1hese roles Is the job of 1he IT Manager (some1imes
called Head of IT or Director of 11). This person has the job of making
sure that the computer systems in an organisation brir,g real benefits
and justify any expense.
Engineers and technicians
Other people nave the specific job of maintaining computer hardware.
These are often cailed computer engineers or computer 1echnicians.
• Computer engineers typically design and build computer hardware
sys1ems, such as processors.
• Computer technicians typically work to fix and maintain hardware
systems onoe they are in use.
Software trainer
A software trainer works with users 10 develop tne skills and
unders1anding they need to make the bes1 use of the software.
M ultimedia artist
A multimedia artist uses computer systems to create original art, whicn
might include visual images, music, video. animation and combinalions
of all of these.
LINK
Find out more about
Systems software: 1.8
ACTIVITY
Collect adverts from 11ewspapers or onllne fer jobs working wHh
computers. Make a note of what qualifications are reqoired and
what the main responsibility of each job is.
Programming: Untt 8
Testing: 7.13
Tne World VVlde Web: 2.3
%
SECTION 1: Multiple-choice questions
1 An online attack on an crganisation's web server
means 1ha: employees and cvstomers cannct
access 1nat company's web site, This is called:
7 MRI and CT scan are two technologies that are
used by which of the following professionals?
a Teacher
cyber bullying
b denial of service
b
Docior
c
c
da1a backup
d
Meteorologist
Police
d
phlshing
a
2 PrecaU11ons taken by organisations to prevent
cybercrime are called:
a Identity the~
propaganda
c espionage
b
d counter measures
3 Software l hat blocks access to a network from
outside is called:
a anti-virus so'tware
b operating system
c biometric
d firewall
4 Robots controlled by computer might replace a
numan worker iri a:
a car factory
b nJrsery
c law court
d hairdresser
5 Soijware that gives answers to problems using
stored models is called:
8 Which of 1nese is a collection of web pages
hosted on a server?
a Website
b Internet
c URL
d Se1,1rch engine
9 A severe event such as a r urricane can destroy
stored information. Which of tnese precautions
w,11 help to deal wnh that problem?
a Use a password
b
Establish a protocol
c
Make a backup
d
Set up a firewall
1o What is a biometric system?
a A robot that can rescue people from danger
b A security syster, 1,JSing physical features
SJch as fingerprlnlS
c
A oompuler that diagnoses medical
conditions
d A type of computer v,r..,s t11at will make
you ill
simulation
b expert system
a
c
applications software
d manual system
6 A system wrere employees can work at home
and connect remotely to '.he company compU1er
Is called:
a 1e1emarketlng
b teleconferencing
c telephony
d 1e1ecommut1ng
Further practice questions
and examples can be found at
www.oxfordsecondary.
corn/9780198437215
SECTION 2: Structured questions
1 Describe four measures 1hat businesses might
use to ensure 1he security of their computer
systems.
2 Fill In tre blanks wtth the appropriate woros
given in the box below.
ldenfliy theft, lv1RI, e-commerce,
CAiv/, Telecommuting
a _ _ _ _ _ _ _ _means doing office
work from a remote location, so that yo.J
don't have lo travel in w a workplace.
b A onmlnal might pretend to be another
person online and take money from
t'neir bank aocoun1. Tnis is called
c
3 Briefly explain the meaning of each of the
following terms.
a Software piracy
b Expert sys!em
C The V\/orld Wide \Neb
d Podcast
4 Choose a type of job, such as law enforcement,
banking or medicine, and explain how
technology might be used by people who do
that job.
_ _ _ _ _ _ _ is software that
controls indvstrial machines which
manvfaoture objects.
d The use of magnets by computers 1o create
two- and three-dimensional Images of 1he
body is _ _ _ _ _ __
e
When a business allows customers to buy
goods or seivices online, this is an example
o' - - - - - -
Further prac!ice questions
and examples can be found at
www.oxfordsecondary.
com/9780198437215
4a Word P-rtocessing
4.1
Editing and formatting text
LEARNING OUTCOMES
Word processing software is
used to edit text and to change
its appearance. In 4.1, ycu will
learn ab0u1 how word processing
fea1ures are used to work wtth text.
Text mea"s a-:y characters, letters
or numbers 1ha: you ca,i 1ype at
lhe keyboard.
In Unit 4a, you will learn about how word processing software is used
10 create documents that are attractive and useful. You will learn how
word processing facilities are used 1o make documents more suttable for
purpose, and how using a word processor can make work easier.
A t the end of this untt. you will find some practice exam questions 10 test
your knowledge.
Editing and formatting
Word processing makes it easy to edtt and format text.
• Editing text means making changes 1o the text content, such as
adding or deleting words and characters.
• Formatting text means changing tne appearance of text, such as
making it larger.
I
I
Mouse pe,nter
Text PO n:er
Figure 4.1.1
1
i
-
-
f-1- I
I Mouse po nter and te<I
pointer
KEY POINTS
• A typeface is the shape and
Pointer and cursor
You will be familiar with the mouse poinler that moves about on tne
computer screen as you move your mouse. V\lhetl you are using word
processing software to edh a document, the mouse pointer takes on a
vertical shape (see Figure 4 .1.1 ). This is sometimes called a text pointer.
When you move the text pointer to anywhere in your document and
click, the cursor appears where you click. The cursor is typically a
flashing vertical bar. Any typing, edtting or formatting you do will happen
wnere 1he cursor is.
style of characlers.
• A font Includes the type'ace
and tre size of the 1ex..
Different fonts are used to make
text plain, fancy, easy 10 read or
to add emphasis.
Insert and delete text
If yOo.J 1ype characters on lhe keybOard, they will appear where the cursor Is.
• Normally, the charae1ers will be inserted in betvveen any words that are
already there. This is called Insert mode.
• In Overtype mode, the characters you type will write over whatever is
there already, deleting it.
i Cut
~
Paste
Figure 4.1.2
I loons
Copy
You can swap between Insert and Overtype mode by pressing the Insert
key on your keyboard . You will use Insert mode most of the time.
If you need to remove text from a document, you can delete tt using the
Baokspace and Delete keys. Backspace removes characters lo lhe left of
the cursor. The Delete key removes charac1ers to the right of tne cursor.
Working with blocks of text
As well as deleting single characters at the cursor. you can select a block
of text and delete it in ore go.
• To select a word you double-click with the mouse (you must click fairly
quickly). To select a paragraph you click three times.
• To select any ot11er block of text, move the text pointer to the start ,
hold down 1he mouse button and drag the pointer 10 the end of lhe
block of text.
The selected 1ext is highlighted, typically with a snaded block. The
highlighted text can be deleted, formatted or moved around in
the document.
Character formatting
EXAM TIP
It is 111,ot e""oug 11 to k""llw
I-low to t<Se for""-&1tti~
fecitures. sucJ., &IS bold
or fo ...t. you ""-t<St aLso
R."'-OW wl-111 a vccl wl1e111,
11°u sJ.iould t<Se t'1el¾,
to
'"""a~e docu""-e....ts .
For ex'.Cll¾pte, bold could
~e used to pick. out
"""-)'OrtClvct Words """ Cl
pcece of text.
To make part of your text stand out you can pick a range of character
formats.
• Make text UPPERCASE or lowercase
• Text size can be larger or sma,ier
• Select a font (the st1::1Le of text} ,hat suits the purpose o' your
document
• Add emphasis with underlining. bold and italic
• Add small characters above or below the main words using ,.b"'"' and
'""~ !I~
To format a block of text, highlight it and then choose a format option
from ,he toolbar of your software. Alternatively, you can choose a
suitable format before you begin to type.
The defautt character format is the size and style of text that you begin
with, before you make any changes.
KEY POINTS
'Default' means '.he normal way tne software will operate if you don't
make any changes.
Move and copy text
The simplest way to move a block of text is to highlight it and drag it to
the ne,_,v place v>/nere you want it to be.
Or you can Copy and Paste.
• Copy: select a block of text and click on the Copy icon on ihe tool
bar (see Figure 4 .1.2). The selected text is copied imo a small area of
memory called the clipboard. You can't see the clipboard, but tne text
is stored there.
• Cut: if you choose the Cut icon Instead of the Copy icon, the selected
block of text will disappear from the document and will be stored in the
clipboard.
• Paste: move the cursor anywhere In tne document and click the
Paste icon. The text stored in the clipboard will be inserted into your
document at the cursor.
, ACTIVITY
I
Use word processing software to
type up a short document. You
can choose anything you like: an
advert, a slory, some scnool work
or an extract from a book such
as this one.
• Produce one version of the
document that has no text
formatting - it is all In the
default style.
• Produce a second version
that uses lots of character
formatting - many different
fonts and sizes and layout
options.
• Produce a third version that has
a small amount of character
formatting - only the headings
and the most important words
are emphasised by formatting.
Which o' the three versions do
yo..i like best?
LINK
%
Find out more about
Text layc,Ji: 4.2
Crea1ing finished documenis: 4.3
Text layout
LEARNING OUTCOMES
In "· 1, you saw new word
processing allows text to be
edited and formatted. In 4.2, you
wlll leam abo~t otner features
that are used to Improve the
layout and appearance of
documents.
Text wrap
Normally; when you are typing a document, tne sof!v,are will arrange the
iext inio lines automatically. When there is no more room on ihe line, the
next word appears on the line below. This Is called text wrapping. The
text will nol wrap In the middle of a word, but only in the space between
words.
If you press the Enter key while you are typing a dowment, this will start
a new line. This is called a manual line break or a hard return.
The only times 1hal you need to use a manual line break are:
••
Ma<1y word processing packages
will display 'II symbols in the text
showing wnere you have entered
manual line breaks and oiher
formatting and layoi,11 fealures.
You can turn this display of' and
on using a tool bar icon. llie
picture above shows w'nat 1his
icon may look like.
Try clicking It to turn i he
lormaWng display on and off.
• when you want '.o break the text into short lines or create a list
• at the end of a paragraph .
If you are typing a long documenl. you should break the text inlo
paragraphs lo make it easier to read .
Line spacing
The lines of text can be close together or there can be a lot of space
between them. This ls called the lir e spacirg. You can set line spacing
fer the whole document or for a block of text.
In general, mere space between lines can make the !ext clearer, but you
can't fit so many lines on a page.
Line justification
The left- and right-hand sides of ;he text are called ihe margins.
When you look al a documeni you will see that the iext is neatly lined
up at one side. Typically, the left margin is s1raight, and the right-hand
margin is irregular. This book is printed in that s1yle.
How words are arranged on a line is called the iext alignment.
• If all new lines start neaily at the lefl-hand margin, this is called leftjustified text. Tnis is the most common default layout. Use this for
normal text.
• If the text is lined up neatly at the right margin, this Is called rightjustified text. Use this for numerical data and when typing your address
at the top of a letter.
• The software can also adjust the spacing between words so that both
the left and right margins are exactly slralghi. This is called fully justified
text. Use this for text that you want lo look like printed material.
Newspaper columns are often laid out using fully justified text.
• If the text is plJ! in the very centre oi the line, with space on the
left and the right, this is called centred text. Use this for headings
and titles.
Tabs
If you want lext lo neatly line up at some olher place on l he page, not
al the margins, then you can use labs. Tabs are points In the document
where text can be Positioned. To move the cursor to the next 'Tab stop' in
the line. you press the Tab key on your keyboard. The posttion of tabs is
sometimes shown on a 11.,ler at the top of a document. See Flgure £ .2.1
for an example.
KEY POINTS
Use tabs to line up columns of words or figures neatly.
If all the lines in a paragraph
except tne firs: are Indented, this
is called a hanging paragraph
Tne ruler at ttie too ot
• , ~ ' • 1 -•
;I
,i,e oocornent shows
me ooov•1ent rrargln
..,,.-
'
I • J • I
•'
..
'
l
ThkS t•xt b1p,s at tht m1.r,in
Ti,e ruler also shows
tnetaoS:op
This
Tekt
I
Text C<l'l be al gned to
me tao Stop
L-- -- - --
r[jl•~
tu J&n• d
To a lab
Columns
~
On •
-c .-
Two
au
Thr••
In some documents, ,ext and images are shown in columns on a page.
Newspapers and newsletters are printed this way.
r
You can use a column layout in your word processed documents.
1
In Vvord, the columns menu is in the Layout tab. When you select ,he
coh,mns button you can choose one, two or lhree columns. Selecting
two or three columns will make your document look more like a
newspaper or magazine page.
~
~
You can add columns to your entire documem er Just to a section of tt.
You will see as you type that the text flows from one oolumn to the next
as each oolumn is filled.
/ ACTIVITY
Br•aks •
Ile.) Lin• Numb•rs •
IColumns
,
b:- Hyphtnatlon •
Use of labs
Figure 4.2.1
A single paragrap'1 can be
indented. This means the
paragraph ,s moved In from the
left margin.
!!
•
l•ft
Rlght
More tolumns...
Figure 4.2.2 I Co•urrns menu
I
1 Collect samples of printed material, such as magazines, which
show the following features:
• fully Justified text
• columns
• tables
• very wide er narrow line spacing.
2 Create a document - either from your own wor1< or by copying
one of l he samples you have collected - that demonslrates some
of these features.
LINK
%
Find out more about
.
Creabng finished docu-nents: 4.3
Document structure
LEARNING OUTCOMES
Page t..,out
You have looked at lhe ~se of
word prooesslng so'tware 10
enable ed~ing and formatting of
lex;, and the layo✓• of text 011
the page. In L.3, you will learn
abou1 word processing features
that allow you 10 structure the
appearance of a oomplete
document.
ul (5 I]
Word precessing sohv,are lets
you create s1andard tex1 styles.
You can define a style for your
normal text and for tr.e titles or
headings used throughout your
text. Using these styles simplifies
formatting.
• 'Heading ' is the name for the iext
style used for tttles or subt11les In
yovr document.
• 'Header' is the repeated text tnat
appears at the top of every p.ige
ln a document.
Take care no1 to confvse these
similar terms.
Sltf
Column<
•
•
•
21
Pc11ta1t
1P
•
Mar9.n1 Orllf\tlllon
•
-
1~
Figure 4.3.1
_J
Undtupt
I Page aycvt features
Page layout
Word processing software gives you a number of facilities that allow you
to change the layout of the pages of the document. Figure 4.3.1 shows
1he tool bar ioons in Word: there will be different ways of selecting 1hese
fea1ures in different applications.
• Margins and size: Margins are 1he white spaces that appear on either
side cf ,he page and at the 1op and bottom. You can set 1he margins
to be larger or smaller. You can also cnange 1he size of the paper
used, to ma1ch tne type thal is in your printer. Use margins and page
size to ensure your document fits the paper tnat you have decided to
print it on.
• Orientation: Your docvment can print out In etther 'landscape' or
'portrait' direction. 'Portrait' means the normal arrangement, wtth the
paper 1aller than it is wide. 'Landscape' means the paper Is turned
sideways so h is wider 1han it is tall. You don't have 10 adjust the paper
in the prin1et: the compU1er will just prim sideways. Use orientation to
make sure the shape of your document fits the type of informa1ion you
want to show.
• Columns: If you look al ,he layout of a newspaper or magazine, lne
text is sometimes set ou1 in columns. The columns are quite narrow,
so several columns can fi1 on one page. Use columns if you want your
document to look like a newspaper.
Use these layout features 10 create tne style of document that suits your
needs. Leaflets. school newspapers or homemade magazines might
require careful use of these layout fea1ures.
Page and section breaks
When you have typed enough text to fill up the page, the software will
automatically start a new page. If you want to start a new page earlier
than this, you use a page break. By entering a page break you force a
new page. In 4.2, you learned about columns in documents. Column
breaks can be Inserted in columns and have a similar effect to page
breaks.
----=.,......... ...........,.~.........-..
.__J
::.,
_.
...,...
J -
..6utt U'la UM, ldl t111e, . . . IN Cllllwt
., • ..,.. ~11\.,,.Atill~
Use page breaks if the natural page break makes your document look
wrong - for Instance, if the break comes in the middle of a list or a
subtitle appears at the bottom of a page, separated from the rest of a
section.
JatWI 1 1► 1
....,t.ctP'llt9Ul'Jlt,OftC110f'I""'
,-O"f'\ Mftft.,,W.,.fN ,,._....,_.-
,..,,.
Scmetimes, when you are creating a document you need a seciion to
look different from the rest of the document. For example, you might
want to Include a landscape table In a mostly portrait document.
tl1tlt• M(beft ...tMaAf 11.atllW~
W:a..Nlilllf,...,.._,
~~..,...
Nci, • YOritft llfttll. •ftlf RM O't""""
-··
.......
Mt\ll9fl eft ""4 ..-.. . . .
To do tnls you would enter a section break into your document. You can
then change the orientation of the page in the new seciion.
IIIMJt•~dieflllft...... fllil't~MW
.......... Mil .... lfL-"5 rtTTftl .....
Headers and footers
lftfel'l•M~-Nlt.Mlfl~IN. . .
ff'CINineftV. ,..,,. . . . _ ... , ... . .ti..
Many newspapers, documents and books have text that appears at the
top and/or the bottom of every page. This can incllJde the name of the
book or the page number.
Figure 4.3.2
I Page and section brea<S
• Text at the top of the page is called a header.
• Text at the bottom of the page is called a footer.
The software will add this text automatically to every page of the
document. If you include a page nvmber, the so'tware will work cut the
number for each page and show that.
If you add the essay tttle, your name and the page number to every page
of an essay, you are less likely to lose pages from your essay or put them
In the wrong order.
Referencing: footnotes and endnotes
You should never use a quote from somebody else's work whhout
referencing where you got it from.
Sometimes a reference is included in the main text in brackets. But often
writers use footnotes or endno,es. They are marked by small numbers
that appear in the text.
/ ACTIVITY ~
Create an article for a school
magazine on a subject you
are Interested In. Experiment with
how to lay out the page, using
columns and other features, to
make It look like a magazine
article.
• Footnotes appear at the bottom of a page.
• Endnotes appear at the end of the ,,fnole document.
LINK
Use footnotes and endnotes for references and other nmes that you
don't want to include in the main ,ext.
Text formatting: 4.1
%
Find out more about
Adding images and other rtems
to documents: 4.4
..
Combining and merging
LEARNING OUTCOMES
In tflis unit, you have leemed aboUi
creating documents by emering,
edtlng and formatling text.
In 4 .4, you w,11 learn about adding
other ttems to documents, sv,:h
as Images, graphs and tables.
Merge documents
Two or more documents can be combined 1ogether to make one large
document. This is called merging the documents.
• Many word processing applications have functions called 'Insert file'
or 'Append', whicn allow you to add files together to make a long
doct.ment.
• Copy and Paste (see 4.1 } can be vsed to copy text from one file
to another.
Use these features when you want to combine several small documents
into one large file.
Import graphics and other items
lns<rt
Table-
[3Pk:tures
'5 Icons
Q Onlint PictuteS
0 30 Modets: •
~ Sh•pe, -
~ Sm,rtArt
T•bl.cs
Qb,nho.tions
The Insert menu
Figure 4.4.1
You can also insert items such as images, graphs and tables.
Figure 4.4.1 shows some of the items ll1at you might be able to
add to your document.
• Picture: You can insert pictures to make your text more interesting. You
can insert pictures from your computer or ones you find online, bUi
make sure you have permission to use them.
• Icons is a oollec1ion of simple images provided for free use wtth word
processing software. This type of image is sometimes called clip-art.
• Shapes, Chart and Smart Art: Features like these allow you to create
graphic images, such as simple diagrams, wtthin the word processing
system.
• From other software: You can often import items from other soltware
applications, such as from a spreadsheet.
.,,,.,, I
I
.I
Ttolf
•
-
I
Figure 4.4.2
-
MT
DD
DD
DD
DD
OD
DODO
Insert table
When you have inserted a picture or other item Into your document ycu
must carefully position it. Formatting features allow you to 'flow' or 'wrap'
text around the image, so that none of your words are covered up by the
picture.
Tables
A table is a grid of columns and rows. N is useful for laying out
Information sucn as a price list or timetable. It makes them easier to
read. Figure 4.4.2 shows a user creating a table with two columns and
five rows. Once a table has been created you can drop the cursor into
any part of the 1able and type In text or numbers.
When a table Is created it Is a simple blank grid wiih lines to show the
columns and rows. VI/here each row and column mee1, a single box
is created. This is called a cell. This simple table can be formatted to
make the table look better and be easier to read . Some ol the formatting
commands available are:
Column width Each column can be set to a width that is right for the
data It holds.
Shading Rows and columns can be shaded different colours to make
them stand out. For example, the heading row at the top of the list is
usually shaded.
Borders are the lines separating each column and row. The style,
thickness and colour of the border can be changed. or it can be
removed altogether.
Text direction can be changed so that it fits in a column at an angle.
This is useful for headings that are too wide to 't in a column.
Cell margins can be made larger or smaller to create the right amount
of space around text in the table.
In \/\lord, 1he formatting menu oan be accessed by right-clicking
anywnere in a 1able. VVord also provides a range of pre-set table formats.
It is often quicker to choose a preset format than to create your own.
Figure 4.4.3 shows some examples of table designs you can choose.
/ ACTIVITY ~
--........
.........
.........
--------------·-•==== ...
... ----• ...,.
===== ......
- .,._ -·~
·- ---------------
..----......
..
--·-··
-····
Figure 4.4.3
-------- -
Select tab e c!es gn
When you have created a table, rows and columns can be added if
needed . It Is also posSJble to split a cell into two or mere smaller cells.
You can also merge two or more cells into one larger cell.
A table is a very useful and flexible way of laying out information neatly
in a word processed document. Figure 4.4.4 shows an example of a
completed table. The user has inserted text into ,he table and chosen a
design.
Emphasise key words
Copy selected text lO cllpboard
lnsen dlpboard text Into document
Set tt.. style end size of chl<1cters
In your last activity you created an
anicie for a school magazine. Add
at least one pieture to this anicle.
It ca<1 be one you made yourself,
or a picture you found on the
internet or elsevmere (make sure
you have permission to use h).
Helpful features
LEARNING OUTCOMES
There are a number o' addr.lonal
helpful reah,res offered by word
processing packages. These are
discussed In 4.5.
Safety features
'Nhen you create a documen1 it is saved as a file. If something goes
wrong, your file may be los1. For tnis reason, many word precessing
applications offer 'safety features' that make It less likely you wlli lose
your work.
• AU1cmatic save: In V\lord, this feature Is called 'Auto-recover'.
Auto-recover Is on and saves your document every 1en minutes
by default.
• Backup: There is a 'Backup' option in most word processor
applica1ions. If you switch it on, two copies of yovr work are saved.
One copy Is for you 1o work on, and the o1her is a safe copy in case
anything goes wrong with the original. In \/\lord, you find the backup
op1ion in the File/ Options/ Advanced me~u.
• Password protection: You can password protect any Word file. Once
you have set a password for a file it must be entered eacn time the file
is opened.
These safety features are useful if your work is very lmportam,
or secret.
Track changes
When 'Track changes' is turned on, 1he computer remembers every edtt
or formatting change you make. Fig1.;re 4 .5.1 shows an example o1 a
document tha1 has been edited wtth 'Track changes' on.
'Track changes' is useful when changes to an important document
need 10 be approved by a more senior person. They can easily check
what edits have been made. It Is useful if more than one person Is
working on a document. Each person can see the changes the other
person has made.
ACTIVITY
Imagine you have been given
a work experience opportunity,
working for a small business.
Your boss asks you to wrtte a
short report en how to make sure
that Important document Jiles are
not lost or spoiled.
Wri1e a short report, using a
word processor, on the software
features that wovld help ihe
business.
Sefial;,eguential file ordering is - __________ -{ Formatted: Font: Bold
where records are stored in a logical
selllcleAeeorder. Records can be
arranged according to name, date,-81'
size or anyotherf,eld. In an office
environment, all- many records are
kept In se EtueAliuelseguential order,
such as employee details, payroll
Information and customer records.
Figure 4.5.1 I Trac< changes - show ng edits and fo,rr,att,ng
Search and replace
Find and replace
A useful fea1ure of most word processing software is the 'Find' tool. This
will search through the document for any word. As well as words you
can search for characters, formatting codes or longer pieces of text.
Use 'Find' when you need 10 find the right Information or a quo1e In a
very long document.
The 'Search and Replace' 1001will find every example of a word and
change It into a different word. This can save you a lot of time when you
need to make a 101 of cnanges to a document, but It needs to be used
carefully.
Spell check
Most word processing software ""~II mark spelling mistakes. Figure 4.5.2
shows an example of a piece of text with 1he spelling mistakes marked .
In this example. the computer displays a red line under the word that is
spelled wrongly.
The compuier will usually suggest the right spelling. Click with the right
mouse button on the word, and you will see a suggested 'right' spelling.
Use a spell check with all your documents to make sure your work is of a
high standard.
In Vvord, the spell check function is found under the 'Review' tab. The
Review tab holds several other useful tools to help you write and check
your documents:
••
A spell checker will be able to
spot if you type a spelling that
does not match its diclionary.
But a spell onecker will not warn
you r. you mix up words. So If you
mix up ~here' and 't'1eir' the spell
checker will not spot 1ha1 mistake.
Thesaurus Hyou highllght a word and click the 'Thesaurus· button,
Word suggests a list of otner words that have a similar meaning.
Word count ,ells you how many words are In your file. This is useful if
you are writing an assignment that has a word limit.
Comments tt you highlight a block of text you can add a comment.
The comment appears in a box in the margil'l. This is useful if you are
reviewing your own or someone else's work.
There are also 'Language' and 'Translate' options that are helpful
if you are working in another language. You can translate text from
one language into another and set the spell-checker to use another
language.
~eotii!f file orderirog is where
records are stored in a logic.at order.
Records can be arranged !tlilllllil!& to
name, date. sfze or any ottJe;d!tld. tn
an office enffloinL many records
are kept in se;ggQtia,lord-er, such as
employee details, payrolllnlonnatiOn
and c:ustomerrecotds-
.
Fig ure 4.5.2 f Spe'I chec<
Mail merge
LEARNING OUTCOMES
Often, bu$inesses want !o se<1d
lhe same letter to ma~y different
people. An example would
be a letter wrth rews of a free
offer, se'lt to all tPelr customers.
lm,tead of typing out tre letter
a hvndred times or More, they
can use a facility known as 'Mail
merge·.
Ahnough h 4.6 the example
of a le'tter is used, you can
use Mall merge wltn all types
of document, not )us! letters.
You can also use Mail merge to
create emails. These .wo pages
will explain how tre Mail merge
•eature works.
Mail merge files
Mail merge uses two files:
• Tne primary file: a word processed doct.1ment such as a letter.
• The dala file: a collection of records, for example the names and
addresses of customers.
The Mail merge facility produces many different copies of tr.e same letter.
each one addressed to a different person from the data file.
Data file (address list)
A database is a collection of data - facts and figures - organised in a
struciured way. YO'J will learn more about databases in Unit 6. Databases
can contain several tables of data. But the data file for Mall merge is just
a single table.
Here is an example of a simple data file.
First name
Surname
Address
Arthur
Brown
55 Oak Road
Sandra
Kenneth
Mills
Lowe
59 Oak Road
27 Lower Avenue
Janice
Potter
99 Port View
The key facts about the data file are as follows.
• Each row of tne table is called a record. A record is all the information
stored about a person. This simple data file has four records. In real ltte
there would be many more.
• Each column of the table is called a field. A field is a single ttem of
information (such as surname). This simple data file has three fields.
• Tne first row of the table gives the names of all tl1e fields in the data
file. In this case they are first name, surname and address.
Data source
The data file that you use for the Mail merge can be:
• created \JSing ,he word processing software
• taken from a spreadsheet or database 1able created by suitable
software
• taken from an online address book.
You mu~ select the data source before you complete the Mail merge.
The primary fi le (letter)
The primary file is typed up like a normal letter. But instead of putting in
details of one person you add field names from the data file.
Figure 4.6.1 shows this process. The user nas selected tne fields 'Firsl
name' and ·Last name' from the list of database fields that are available,
arid Inserted them into the letter.
_J
High gl
M.ro• F1t1
Address Grtttlno lnstrt Mtr
Block
Un•
Fltld •
Wrrt• & ~
t,-----------4
• • · •··•1
-..2
. ----.
~- '
Flmnam•
Sumamt
Addrtss
pear «!;F,]i.r~~[1....:n
9'.a1:!J)Q.;D-~-~~>>.1~~~
-~:gqi!)
_p~-~
..,!l..-~~!'
. -•
Figure 4.6.1
I Ma, me•ge insert ng le'Cls
Performing the Mail merge
The Mail merge is carried out by merging the data file and the
primary me.
• The structure of the letter is taken from the primary file.
• A letter is created for each record In the data file. Tne name. address
and other details for each letter are taken from the data file and used
wherever there ls a field name In 1he primary file.
Advantages of Mail merge
Mail merge can save a great deal of time. In this example, 1ne letter only
has to be typed once but four copies are made, each addressed to a
different person.
/ ACTIVITY
I
Imagine you are on wo~ experience, working for a photographer.
He wants to send a letter to everyone on a list of people who are
about to ge: married, advertising his wedding pncto service.
You offer to help him by using Mali merge.
LINK
You will need to create a primary file and a data file. The data file
should contain at least three fields and five records.
Find out more about
Databases: 6.1
%
Creating a table of
contents
LEARNING OUTCOMES
In 4,7, you wlll tearn how using
lex: styles allows you to use
automatic features suoh as
table of contents (ToC). You will
learn how ,o add a ToC •o yevr
document$.
Using a table of contents
If you are using a book to find information for an assignment you will
often wa'lt 10 find a relevant section in lhe book. To do this you use the
table of contents, which Is found at lhe start of the book. The table of
contenls lists lhe headings of each section and ti1e main subsections in
a book. ft ,,All tell you what page a seelion starts on.
Mosl word processor applications have a function that allows you to
create and vpdate a table of contents (foC) aUlomatically. This can be a
helpful function. especially where you have long documents with many
sections and subsections.
Using styles in your documents
In 4. 1, you learned how lo use format options to change lhe
appearance of blocks of text . For example, you can create a heading
by increasing the size of a font and making the text bold. Another
way to create headings and other special text features is 10 use text
styles .
AaBbCcOc
AaBbC< AaBbCcC f.
UNormal
Heading 1
Figure 4.7 .1
Heading 2
I Sty'e rrenu
There are advantages to using styles:
You do not have lo accept me
default apPe?rance of a heading
style. You can edil a style so that
headings and Oiher text styles
appear how you wam them l o. ~
you edit a style all insta0 oes of~ in
your document will c/1aoge.
• It is quicker and easier to use styles tnan format oplions.
• If you decide lo change the appearance of a heading, you only need to
edit lne style. The changes you make are applied lo every heading that
uses the style.
• Using styles allows you to use olher special features in your word
processor. For example, in Microsoft 'Nord you musl use styles if you
want to use the table of ocntents feature.
Create a table of contents (ToC)
•• •
There are two steps 10 creating a ToC:
In large documen;s you might
want to use sub-headings
wtthin main sections. If you use
the sty1e heading number 2 for
subheadlngs, they will appear in
the table of ooments.
1 Make sure that all your headings are created using styles. You
will vsually use the style called Heading 1 for ycur main headings,
Heading 2 for subheadings, and so on.
2 Create a Toe by selecting the Table of Contents menu and selecting
one of 1he ToC s1y1es. In Word, the Toe menu is in the References
tab. This may vary in other word processing software.
/ ACTIVITY
Insert
9> AddTnl •
Pag• Layout
AE -.r,,,1ln5'rt Endnote
[='I! Updat• Table
Insert
Footnote
I
Conttnh ,..
Rtfenncu
~ Nm Footnot, •
..J :,ho, t '-
I
Mailing
~~
Insert
Citation • I
Built·ln
Autom.tlc Table 1
Add a table of oonlents to one
of the documents that you have
created earlier in tnis chapter.
For example, the article you
wrote In 6.3 or the report in 6.5.
Remember, you will need to edtt
the document to use styles for
your headings.
Coalfl\lY
·-·-------------------,_ ,__________________
·-•------------···-------_
Automattic Table 2
Table or Ctm.trnlS
·-•-----------------,......,_-______________________
_
l...._, J _ _ _ _ _ _ _ _ __
Figure 4.7 .2
ToC menu
Updating a Toe
You don't have to wait until you have completed a document before yov
create a ToC. Once you have added a Toe you can keep adding text
and headings to your document. Your word processor will keep !rack of
all your changes and update tne TOG when you choose. New headings
will appear in your ToC and the page numbers will be updated.
More reasons to use styles
In this seclion, you have learned how using sty1es to crea1e headings.
which allow you to create and update a Toe. Some other reasons to use
styles instead of format options are:
• It Is easy to change the design of a document.
• It is easier to save documents as web pages.
• Adding captions to pictures Is improved.
-----·
--·---..
--Figure 4.7.3
Upda:ng a ToC
Using forms to collect
data
LEARNING OUTCOMES
In 4.8, you will learn how forl"ls
are used to caplure i~forma11on
and now they can be created for
use onllne.
Fillable forms
A fillable form is used to capture information accurately. Fillable forms are
very common on lhe WWW. We use forms when:
• placing an order onllne
• setting up a social media accoun1
• answering a survey or quiz.
In fact, we use forms almost every time we send Information over
lhe internet
Register for an IT revision d~ss
Class:
Name:
RlcardoSMW
:Cho!,i,Jeant
5'Jbje<,t:
□ Spreadshffts
10.
0 Databases
10b
10c
□
Figure 4.8.1
A 'i ao e fo,m
Advantages of fillable forms
A fillable form:
• gels !he same informalion in the same format from everyone who uses n
• is easy to complete
• reduces lhe possibility of mistakes and spelling errors.
Fillable form controls
I' you are creating a form using
Word you m~s1 use menu options
on the Developer tab. You may
need to add the Developer tab
to your Menu Ribbon 1,5ing Flle /
Oplions / Cu~omlse Ribbon.
A fillable form comains features called controls lhal make ii easy 10 enter
dala. Some of lne common controls you will find in forms are:
Text content allows a user to enter !ext as they choose. Examples are
name and address.
Check box Boxes that users can tick to indicate a choice. For example,
clicking a 'male' or 'female' box to indicale gender.
Drop down list Clicking lhe conlrol opens a list of options for lhe user
lo choose from. An example is a control that allows a user lo say V1/na1
counlry they live in.
Date picker shows a calendar to a user to make ii easier lo
enter dates. This cont1ol can be used wnen emering dale ot birth,
fer example.
Picture content allows a user to click a picture to enter da1a. An
example is a form where users lndical e a choice by tlcking a tick for 'yes '
or a cross for 'no'.
Creating fillable forms
There are four steps to creallng a fillable form:
1 Decide what data you need to capture Make a list ol lhe
Information needed on your form. For each piece of data decide
which control will capture it best. Example: tt you need to cap1ure a
date of birth, use 1he date picker ccni rol.
2 Design your form Lay oUt 1he headings for your form In 1he order
you want the data. If it helps, use a table.
3 Add controls to your form When you are happy with your design,
add a control lo each heading on the form. You will need to set
propenies for some controls. For example, tt you use a drop down
list control you will need use properties 10 say which rtems are in
the list.
In this unit, Word Is used to
demonstrate how fillable forms
can be e<eated. Th~e are many
other applications tr'8t can be
used. They will all use similar
fea1ures to those described In this
lesson.
,
Day:
::.Jonday
Tuesday
\Vednesday
Thursday
Friday
Figure 4.8.2
Use prcoert es to set choces n drop down contra'
/ ACTIVITY
4 Test your form When creating a form in \/1/ord you should save it
as a template. To test the form you should open a new document
using the form 1emplate. You can 1hen test all the controls to
make sure 1hey work as you intended !hem to. If you need 10
make any correo1ions, open the template you created and make
them in thal docoment.
Your 1eacher is planning to offer
some workshops in programming
and applications such as Excel to
help st\Jdents prepare for exams.
Students will complete a form
or>llne to provide their name,
class and date of birth and select
what application work~ops they
want to attend.
Design and test a form to collect
this Information.
•
4b Well page
4.9
LEARNING OUTCOMES
In 4.9, you wlll tearn about how
a collecHon of web pages Is put
together to make a webstte.
What is a website?
In Untt 4b, you will learn how to create a web page that can be accessed
by internet users all over the world. You wlll learn how web designers
make decisions about the appearance and function of a webstte, ar d
aboul tne software that is available to help wtth this work.
Al the end of the uni1are some practice exam ques'.ions to test your
knowledge.
Web server
KEY POINTS
• Upload: Wr>en you pu: content
on a web server for other
people to look a1 or use you
'upload' the content.
• Download: When you '.ake
content from a web server
on to your computer you
'download' the content.
A web server is a computer that is connected to the internet. Internet
content is stored on the web server. We say that the content is hosted
on tne web server.
A person who wanl s to share content on the internet will upload the
content to a server.
People t.Slng the internet can connect to the web server and download
tne content.
Web browser
The software you use to connect to the internet is called a web browser.
Examples include Internet Explorer, Microsoft Edge, Google Chrome and
Mozilla Fire'ox.
In 2.3, you learned that every web page has an address called a URL
(Unttorm Resource Locaw~. If you type the URL Into tne address bar of
the web browser, the software will:
• connect to that URL
• download the content from that URL
• display it on the screen of your computer.
Web pages
·
,----__ .-
---,---
Flgu,... 4 .9.1
A web page is a document that appears in the
browser window. It can include text, Images and
animated or interactive content. This content is
downloaded from a web server.
Figure 4.9.1 shows an example of a web page
that was created and maimained by the Jamaica
Tourist Board.
The content of web pages need not stay the
same. \l</eb pages are quite easy to change.
Next time yov look at a web page it might look
very different.
Website
•• •
A website is a collection ol web pages on the same topic. Typically:
Here are some examples of
domain names:
• all the web pages are hosted Of'\ the same web server
• all the web pages have a similar design
• all the web pages have similar URLs.
All the pages on the website are created, controlled and mainlalned by
lhe same person or organisation.
Web page address
The address of a web page is called the URL. A URL starts with the
letters:
http://
Jamaican goverPment Information
Service
http://www.jis.gov.jm
University ofTnnidad http://u.tt
lmer'l8tional Criokel Council
https://www.icc-cricket.com
CXC nttp://www.cxo.org
Nolesmaster
htlp://,wN1,notesmaster.com
or
https://
http stands for 'hypertext transfer pro'.ocol'. which is the
communications protocol for the internet. Find out more about what a
proiocol is in 2.3. https is a secure version of http. Data sent across !he
inlernet from a https site is protected so that it cannot be intercepted
and read .
The next pan of the URL after http:// is lhe domain name. n,., domain
name identifies where the web page is hosted and who controls er owns
lhe website.
The URL of a web page is the domain name followed by a forward
slash and the name of the page. For example, 1he domain name for the
International Cricket Council (ICC) is:
https ://www.icc-cricket.com/
/ ACTIVITY
1 Find out the two-letter
lnlernational code for at leas,
five nalions In the Caribbean.
2 Find out the domain name for
three different websites that
are registered in your country.
You could :ry to find the
website for the government
the local university, a school or
af'ly large local busir ess.
The address of the ICC web page about women's crickel is:
https://www.icc-cricket.ccmlteams/women
International codes
Many domain names end in a dot followed by a two-letter code that
identifies the country in which the domain is registered. The 'Did you
know?' box in the margin shows some domain names. You will see that
a domain in Jamaica ends with the letters .jm. A domain in Trinidad and
Tobago ends with the letters .n.
Hosting service
%
If you want to upload a website to the internet you do not have 10
operate your own web server. Internet companies run large web servers.
For a fee they will host your web page on lheir server.
LINK
Hosting services sometimes also offer web design and creation
services. As well as hosting 1he website, they will help you to make tt
and to maintain It. They might also offer features linked to the website,
such as email.
Key internet terms such as URL
and protocol: 2.3
Find out more about
Planning a website: 4.10
Planning the website
LEARNING OUTCOMES
In"·10. you will learn abou:
lhe design and structure o1
a website. \f\lhen you plan a
website you Mvst think abo\Jl Its
purpose and ils audience. You
m..,st also make decisions abou,
lhe co~lent of the stte tl'a: reflect
how It will be ..sed.
Purpose
Every webstte is set up for a purpose. Here are some examples:
• a webstte to promote a particvlar point ol view, such as a political
opinion, or to persuade people to do something, such as vote
• a website to advertise a product or service
• a website tha! lets you buy things
• an educational Informative website where you can find things out
• a social 1.vebsite where people can share content and make friends.
The webstte content should reflect 1he purpose. For example, an
educational webstte should contain clear information. A business stte
should be more formal than a s~e sel up for fun.
The website might also have fea1ures tnal reflect tts purpose. For
example, a website that sells a product will have facilities to process
paymenis online.
Audience
When you design a website you must think about wno will look at it - its
audience. The website design and content should be suitable for that
audience. Here are some considerations.
• Use a style of language suitable for your audience. Children might
pre'er simple language; older people might prefer more fcrmal
language.
• Is your audience familiar with 1he internet? If so, you can use more
complex interactive facilities.
• How cari you use Images and pho1ographs to make your con1eni
clearer to the audience?
• Sometimes, complicated information is easier to explain in a graph or
chart.
Pages
You have learned tnat a website Is made up of pages. All the pages have
the same domain name.
In planning a website, you must decide:
• how mariy pages it will have
• what content should go on each page.
If you have three differen11opics 10 talk about on your website, then you
might want to create three pages, one for each topic.
If a school sets up a webstte, there m1gh1 be a page for each class in
the school.
Home page
The home page is the page you see v,l hen you first connect to tne
website. It is the defautt page. If you type only the domain name then
you will connect to the home page.
The home page will typically have:
• a general description or introduction 10 the site
• hyperlinks to the other pages on the website (see the 'Key points' box
for an explanation of what a hyperlink is).
If there are a lot of pages on the site, then there might not be links 10
every page from the home page. For example. a school website mignt
have links to a page for eacn class in the sohool. On each ctass page
there might be links 10 the pages for each pupil in the class.
KEY POINTS
A hyperlink ls a oo~nectlon from
one websrte to another.
It 1s usually shown as l'ighlighted
tex1.
\.Yhen you click on the hyperllnk
ll'e browser will connect to tne
tir ked web page,
Hyperllnks are often just called
'links'.
Finding the right page on a site
You want your website vsers to be able to find oontent on the site.
• Sometimes a website has a page of links to site content. This migllt be
called an index page or a menu page.
• Another option is for the site to have a menu bar (often on the left of
every page) with links to the main areas of the site.
• Most sites have a search box. You type In the topic you are interested
In and the site search engine v.i ll link you to the right page.
Design and layout
When you are clear about the audience and purpose of the website you
can make sensible decisions about the design and layout to use.
• The design of lhe website includes oonsideralions such as the colours,
fonts and Images that you will use.
• The layout of the website includes issues such as the menu bar, the
use of white space and the use of images.
Modern websites are usually designed so tnat every page on the site has
a similar design and layout. This helps the user to wor1< with the site and
makes it seem more professional.
/ ACTIVITY
I
In this section, 1here Is a list of reasons for setting up a website
(promoting a point of view, adVertising, buying and selli~g. informing
and social networking).
Find an example of a website that has been set up for each one of
these purposes.
For each website note down:
• 111e URL of the nome page
• 1he main purpose of the website
• the most likely audience for the website.
Comment on the way the site Is designed - is It suitable for Its
audience? Does it have a menu or a search box to help you find the
content you want?
,
LINK
%
Find out more about
Domain name. web page and
other key terms: 4.9
Adding content and links to web
pages: 4.11
Creating a web page content and design
LEARNING OUTCOMES
In "· 11, you will learn about how
web content is createcJ ready to
be uploacJecJ to a web server.
Some HTML editing so'tware
will show you exactly what your
web page will look like vvhen n is
published on tne Internet.
Toe ierm fer this type of edttor is
'\/Vhat You See Is What You Get'.
Toe abbreviation for this
is WYSIWYG, pronou">oecl
'wizzy-wlg'.
HTML
'Neb pages are written in a computer language called HTML. This stancJs
for Hypertexl Markup Language. Hypertext Is text tnat includes links and
other features found on web pages . \/Veb browser software (such as
Internet Explorer) can read HTlvlL. Tne HTML tells 1he web browser what
to display on ,he screen.
HTML uses tags, which are enclosed in angle-brackets like this<>.
When the HTML is read by a web browser the tags do not appear, b\J1
they tell the web browser what to display. HTML can be used to set text
features and include images. If you know HTML you oan type it directly
using a simple text editor, sucn as MiClosoft Notepad.
Software
Instead of wriling HTML, you may pre'er 10 use web authoring software,
also called an HTML ed~or. This Is software that allows you to design
the appearance and con1ent of a web page. The software converts your
design Into HTML, ready to be used as a web page.
There are many different authoring software applications for sale. Adobe
Dreamweaver is one of the most popular. There are also free 'shareware'
packages available to create web pages. KompoZer ls an example. Most
word processors such as Microsoft Word will allow you to save a page
thal you have designed in a web page format.
Enter text and images
All web authoring applications will allow you to type in the ,ext content of
a web page. In general, the appearance and functionality is similar to a
word processing system. There is a tool bar with format choices, which
you apply to the oonlent you enter. Features such as copy and paste are
available.
If you want to include an image on a web page, the file with the image
must be stored on 1he web server. The web page will include HTML
commands that Instruct tre browser to locate the image file on the
server and display tt on the web page. If the file Is net available, an error
message w,11 appear on the web page.
The web authoring application will allow you iO specify where the
image will appear on your web page and how the text will wrap or
flow around it.
An image, colour or pattern can be used as the background to a
web page.
Design and layout
In some cases, each page on a webstte has a different design and
layout. HTML commands are available that set text size and layout and
1he use of tables and other fealures. V\/eb authoring software will allow
you to choose these options.
However, it is more common nowadays for all the pages on a website
lo use a common templale or style sheet A slandard layoUl is chosen,
together with design choices such as colours and background.
The people creallng each page enter tne text and other content, and a
web page is created that puls the page con1ent into 1he standard stte
layout and design.
Links
An Important feature ot a websile is 1he use of hyperlinks. The HTML
command for a hyperlink looks like this:
<a href='xxxxx'>llnk text</a>
lnslead of xxxxx you would type the URL of the web page you wish to
link to. lnS1ead of link text you would type 1he words you wan1 to show in
your link.
Many types of link are available.
• The most common link ls to another web page. The HTML for this type
of link is shown above.
• You can also link to a location within a web page. An HTML tag called
a 'bookmark' is added to the page content. It is no'. shown on the
screen. but you can create a link that goes straight to the bookmark.
• Link to an email address. A hyperlink to an email address "'~II cause
your computer to start up tne installed email software wtth tne email
address entered, ready to write and send an email.
• Link to user-created files. You can link to Images, and other files, so
long as they are slored in a location that is accessible by other internel
compulers. Many people use web pages to link to collectlons of
holiday snaps, for example.
Thumbnail
/ ACTIVITY
I
Use web authoring software
to create a web page with
Information abol.1 a topic that
you are interested In. It should
Include:
• 1ext
• links
• Images
• suitable design choices.
A link lo a web page or to a photo or other image can be shown as a
tiny picture, no bigger than a thumbnail.
These 'thumbnails' work as hyperlinks. A user can click on the thumbnail
Image to see the full size picture or to go to 1he web page.
Entering links and thumbnails
As Ieng as you kl1ow the URL or file location that you want to link
10, web authoring software provides the facilities to create all types
of hyperlink.
LINK
Find out more about
Planning a web page: .i.10
Publishing a web page: 4.12
%
Publishing a web page
LEARNING OUTCOMES
'Pvblishlng' a web page means
uploading It to a sui:able web
seNer and connecting ii lo ihe
internet so that anyone can
download it and look at 1he
contem i" their web browser.
These 1Wo pages are about the
tasks Involved in making 1hls
happen.
Register a domain name
An organisation called 1he lmernet Corpora1ion for Assigned Names and
Numbers (ICANN) controls the domain names used on '.he internet.
Domain names are divided Into groups called Top Level Domains (TLDs)
according lo the final letters of the domain name. such as .com or .net.
This final code tells you the country or the ca1egory of webstte.
!CANN delegates responsibiltty for each TLD 10 domain registries in
different countries around lne world.
A domain registry keeps a database of all domain names in tha1 TLD
group. Registries charge an annual fee for giving a domain name to a
user. People and organisations can register a domain name directly with
the registry, or via a web hosting seNioe or other computer company.
IP address
Every webstte has an IP address QP stands for lnterr.el Protocol). The IP
address is a long and complex number. A domain name is much easier
10 remember than an IP address. Wnen you register a name tt is linked
to your IP address so that anyone typing the domain name in their web
browser will connect lo your website.
Upload content
When an individual user wishes to publish a web page, 1he HTML file
of the web page, and any other files such as images, documents and
other items, mus1 be transferred to a web seNer that is connected to the
in1ernet. This is called 'publishing' the web page.
Web hosting service
Web hos1s are companies that provide space on a web seNer with
ln1ernet connectivtty.
••
In March 2017, ihere were 330
million domain names on 1he
iriternet. Tne number of web
pages is very muc,'l higher 1han
this.
Many Internet SeNice Providers (ISPs) offer this service free to 1heir
subscribers. Tr.ere are also companies who specialise in hosting web
sites; GoDaddy Is an example. Hosting companies will provide servl=
such as aU:horlng tools, online shopping functions and email. Personal
website hosting is generally quite inexpensive. Business website hosting
can cost much more because businesses often want larger websites
wnh more seNices.
Use FTP to upload files
File Transfer Protocol (FTP) is the network communications protocol that
you use to copy a file from one computer to another over a netv,ork,
such as the internet You typically use FTP to upload files to the web
server.
Test the page
•• •
Companies will pay big fees for
the righl to use pcpular domain
names. For example. 849.7 million
was paid In 2010 for the domain
name Carinsurance.com,
You should test the web page at every stage of the process, both be:ore
it is uploaded and alter it is published. Make notes about t11e results of
your tests and make any changes or amendments to the web page.
Your web authoring software will give you a general impression
of what the final web page will look like, but it Isn't until you have
published and iested it that you will know for certain tnat it looks and
functions just as you want ii to.
Use a web browser
There are several different web browsers available. They handle HTML
files slightly differently. You should make sure that the page displays
correctly using all common web browsers.
Test links
Your web page will include one or more hyperlinks. Test a link by clicking
on it and making sure It connects to the righl web page. Also test any
other onllne functions such as emailing and video clips.
Test audiences
1Nhen you began planning the web page or site, you chose the audience
for the site {for example, children, or people wiih a panicular interest).
This is 111e target audience for your site.
Ask people in your target audience to test the site. They should try it out,
looking at the content and using any functions. If they find It difficult or
confusing to use then the site needs to be made simpler.
ACTIVITY
Carry out one or both of the following.
1 In the activity in 4.11, you created web content. Publish this web
content to a web server, and test It to make sure it works as you
want ii to.
2 In the acti\/rty in 4.10, you evaluated a website. Prepare a deta·led
report on the stte, i,xpla ning its structure and any functions it
oonta ns. Test its web links and any othe" functions. If tt Is a very
large site, pick one or two pages for testing.
LINK
%
Find out more about
VVeb hostirig and otrer key
terms: 4.9
Creaiing web cement: ,1._ 11
:
SECTION 1: Multiple-choice questions
1 Draggirg I/le mouse arrow over text to nighlight
rt Is called:
a framing
6 ti the left margin of a document 1s Udy and
s1raigh1, and 1"e rignt margin Is ragged, the
document Is:
b skelching
c selecting
a
b
righ: justttled
left justified
d pointirg
c
'ully justified
d
half Justified
2 A srnaller, raised character set hlg,,er 1han 1he
main lext is referred 10 as:
superscript
b subscript
a
C
embedded
d
highlighted
3 To move a section of text from one plaoe ha
document to another you would use:
a
pas:e and 0t.,1
b
copy and paste
cut and copy
c
d cut and paste
4 What is Mall merge used for?
To produce many documents, wtth
differences between tbeM
b To merge two documents toge1her to create
a large composlte document
c To in.sen emails 1n10 a document
a
d To check for data errors
5 Vvh1ch of the following is NOT a formatting
feah,re?
a Changing :he size o' 1ex1
b Adjusting the line spacing
c Using traci< changes
d Bold a11d ttalio
7 Whi;lt Is 'landso.ipe orientation'?
a Tre document is printed so tt is wider tnan It
is :.ill
b Tile left and right margins are neat and tidy
c Trere is room In the document for a large
graphical Image
d Each page has a needer and a footer
8 Which fe;ilure helps you to spot typirg
mistakes?
a Track changes
b Spell check
c Search and replace
d Tresaurus
9 Whal is overtype mode?
a Making ,he font larger
b Text that appears at the 1op of each page in
,he document
c
The :ext you enter w,11 wrrte over what 1s
:here already
d
Default character formatting
10 When should you use a manual line break?
a At the end of every hne of yoJr document
b At the very end of the document
c To start a new page
d At the end of every paragraph
Further practice questions
and examples can be found at
www.oxfordsecondary.
com/g7801984372 15
SECTION 2: Structured questions
1 A commercial bank wants to Inform c1,1stomers
about its upcoming loan sale. In addhlofl to
placing advertisements In 1he dally newspapers,
the bank would like to send a personalised letter
to customers. kc, the secretary In the bank's
communications department, you are asked to
use a word processing applicatlon to generate
personalised letters to each customer. Outline
the actions you would take to generate the
personalised letters.
2 A student has created a leaflet to tell people
abotrt a barbec.;e that Is to 1ake place In her
town. At the moment 1he leaflet is just plain
text. Explain how l he student could make the
leaflel more interesting, by using a range of word
processing features.
3 Many word processir g applications offer 'safety
fe.itures' tnat make It less likely you wlll lose
your worl<. These are particularly use'ul ff your
document Is very important or secret. Describe
three of tnese safety features.
4 Explain the difference betvveen 'editing ' and
'formatting' 1ext. and wny e.ich is useful.
Further practice qJestions
and examples can be found al
wv,,w.oxfordsecondary.
com/9780198437215
SECTION 1: Multlple-cholce questions
1 \l\lhen you put content on lo a web page for
people to look al lhis is called:
a
b
c
d
downloading
copy and paste
1eleconferenciog
uploading
2 The software you use to connec11o the Internet
is called:
a web browser
b
web page editor
c
searcn engine
network server
d
3 \1\/hat is a i'\yperlink?
a
A wireless device you can use to look at
websites
b A popular webstte ,,vhh lots of contenl
c
A connection from one web page lo ano1her
d A fast l'lternet cable
4 The main page of a website. with links to the
other pages, ls called:
a web server
b
home page
web developmenl server
d master page
c
5 \l\leb pages are written In a language called:
a
URL
b
Machine Code
7 Which 1ype of software wdl help you to create a
working web page?
a Web page compiler
b High level language
c Operating system
d Web authoring software
8 What does a web hosting service do?
a Run an Internet cafe
b Provide space on a server io hold your
website
c Teach children how 10 use computers
d Buy and sell mobile devices 1hat can
access the Internet
9 Which of lnese is a network communications
proloool that you can use to copy a file from one
comp..rter to anolher over a communication link?
a Wiklpedia
b FTP
c Hyperti'1k
d Web browser
10 EvefY website has an IP address. Which o'
these is an IP address?
a A long number sucn as 216.27.61.137
b A series of words such as \w,1w.google.corn
A location such as Kingston
d A compUler type such as Apple
c
HTML
d Pascal
c
6 An important feature of a webstte is the use of
li 0 ks. The command to create a link looks like
this:
<a hrel='xxxxx'>llnk text</a>
\l\lhat should go in place of the xxxx?
a The URL of a web page
b The name of an i'liernet server
A password
d A message to 1he person looking a11he
web page
c
Further practice questions
and examples can be foond at
www.oxfordsecondary.
corn/9780198437215
SECTION 2: Structured questions
1 Explain '.he difference between a website and a
web page.
2 Defir e each of the following 1erms.
a VVeb seNer
b Search engine
c Hosting seNice
d Domain name
3 Explain why a website might nave a link to an
email address. VVhat nappens when a person
clicks on 1hat link?
4 What ls web authoring software used for?
Furtlier practioe queslions
and examples can be found at
wvffl.oxfordseoondary.
com/978019843721 5
Introduction to
spreadsheets
LEARNING OUTCOMES
In 5.1, you wlll tearn about the
purpose of a spreadsheet and
how It Is structJred to allow you
10 enter, display ar,d ma~ipulate
data.
In Unit 5, you wlll learn about how spreadsheet software Is used to se1 out
calculations and 10 present numerical informa1ion using grapns and tables.
At 1he end of 1he unil are some practice exam questions 10 test your
kno,-.1edge.
Wh at is a spreadsheet?
In the days before computers, calculations were se1 out in books called
ledgers that were divided inlo rows and columns. Tne numbers 1hen had
to be added up by hand.
Spreadsheet software Improves this process. Numbers are entered
Into a grid o' rows and columns. After 1he numbers are entered, the
software can calculate the results automatically. If any of the numbers are
changed. ll1en the answer updates aulomatically.
Functions of a spreadsheet
A spreadshee1 can be used to:
• capture data: the spreadsheet allows 1he user 10 enter data into a
structure so 1hat it is organised
• manipulate data: spreadshee: software can carry out a wide range
of mathematical calculations from simple addttion, working out
percentages and averages, lo complex stalistical formulas
• display data: the spreadsheet can se1 out the results in a neat form .
In 5.5, you will learn how to format the appearance of a spreadsheet.
The software will also creale grapns and charts. You will learn more
about this in 5. 12.
Structure of a spreadsheet
Figure 5.1 .1 shows part of a spreadsheet. Some of its key features are
marked.
• Rows: The spreadsheet rows are numbered. In Figure 5.1.1 , you can
see rows 1 to 8.
Rows 1aencfad by number
\:
•
••
a
•
•
••
.........
Figure 5.1.1
•
•
.,• •
co,un'<ls ldent fed by le:ter
'
•
.
•
•
.,
I Structure of a spreadsheet
•
•
•
CellC3
• Columns: The spreadsheet oolumns have letters. In Figure 5.1 .1, you
can see columns A to H.
• Cells: Where a row and a column cross that makes a cell. In
Figure 5.1.1, cell C3 has been seleeted.
You select a cell by clicking on it with a mouse pointer. Each cell has
an 'address' made up of the column it is in and the row it is in. In tnis
example the cell address is C3.
' ACTIVITY I
Open a spreadsheet package
and enter the names and ages of
everyone In your class a1 school.
Each name and age should
appear in a different cell.
1 What range of cells have you
used 10 enter the data?
Range of cells
Figure 5.1.2 shows a cell range. A range is a group of connected cells.
You select it by dragging the mouse poin1er from the top left to the
bot1om righi of the selection. The range is ldentttied by the address
of tne top-left and bottom-right cells in the range. In tnis example, the
range that has been selected Is B2:C6.
•
•
•I
•
•
I
I
•
•
2 What is tne cell address of the
cell with your name in Ii?
•
•I
•
•'
••••
•
Call '1lnge B2:C6
Figure 5.1.2
Ce'I range
Entering data
••
You enter data by selecting a cell 1hen 1yping the data you want to store
In that cell. There are two main types of data 1hat can be entered into a
spreadsheet.
Some1lmes you may want tne
spre.,dsheet software to treat a
number as a label. To do tha1. you
type a single quote mark before
you type lhe number.
• Values: these are numbers tha1 can be used in calculations. If you type
any number into a spreadshee1cell then it will be treated as a value.
• Labels: 1hese are all other types of data, entered as titles and
headings. If you type anytning except a number in1o a spreadsnee1 cell
then this will be trea1ed as a label.
Figure 5.1.3 shows a value
and a label entered into a
spreadsheet.
Cell B2 contains the label
'Height'. Cell B3 contains the
value 1.3.
Note that the label Is leftJustified wtthin the ce!I, ard the
value is right-justified.
n
- • • •
,...c\Jt
'
I
• c•
S,
u
•
•
•
Figure 5.1.3
For example, '2019 can be
entered to label a row for the year
2019.
l
LINK
Find out more about
Calculations: 5.3
Forma!ilng: 5.5
I Label and value
Graphs: 5.12
%
Arithmetic and logical
operators
LEARNING OUTCOMES
In 5.2, you will learn about
lhe three types of operators
you need 10 use when wri1ing
formulas in a spreadsheet. Tl'e
:ypes of operators are arithmetic,
relatlo'llll and logical. You will
use W"8.t you learn In 5.2 when
you study program design ard
implemen,ation
When you use a spreadsheet you will create formulas to carry oUt
calculalions. Sometimes you will create a formvla that carries out one
action if certain conditions are met and another ff they are not. \lvhenever
you create a formula you will use operators. This section explains the
operators you will need to use, along with examples.
Operators
There are three types of 'operator' that you need lo know about.
Arithmetic operators such as + and • are used to perform calculations,
for example, when you need to add two values together; total = number
1 + number 2.
Relational operators such as < and <= are used to compare values lo
create logical tests.
Logical operators described in this section are used to combine logical
statements to create more complex logical tests.
Arithmetic operators
Spreadsheet formulas that calculate values use symbols called
arithmetic operators. You will be familiar wtth these from your study of
mathematics, though some of ihe symbols used may vary from those
you use in maths.
You should know ,he arithmelic operators in Figure 5.2.1.
Operator
Meaning
Example of use
+
Add
Totalpay = BasicPay + Bonvs
•
Subtract
Mulllply
NetPay = TotalPay - Tax
Days = \f\leeks • 7
'
Divide
Days = Hours/24
I
Figure 5.2.1
I AnthfT"et c operators
Relational operators
Somellmes you will use formulas in spreadsheets 10 make a choice
between two actions. This is called a conditional statement. If a condition
is true, carry out an action.
Example: If tt is raining, pul up your umbrella.
Conditional statements use logical tests. The logical test In lne example
is 'It is raining'.
All conditional statements depend on logical tests. A logical lest is one
1ha1 has ihe answer Yes/No (or True/False).
'Wnal is your age?' is nol a logical lest, because It can have many
different answers.
'Are you under 20?' is a logical test, because It has the answer Yes
or No.
Relational operators are used when we create conditional stalements.
Here Is an example: 'ExamMark > 49'
This means 'Is the exam mark GREATER THAN 49?'
> is a relational operator. It means 'is grealer than'.
In this example, if exam mark is 56 lhen 'ExamMark > 49' is True.
Figure 5.2.2 shows the relalional operators lhat you should know.
Operator
M eaning
Example of use
<
>
Is less than
Is grealer than
4 < 100
0.5 > 0.25
=
<=
Is equal lo
Is less than or equal 10
3' 4 = 12
Age<= 18
>=
<>
Is grealer than or equal to
Is nol equal lo (somelimes the
symbol c# Is used)
Height >= 1.5m
25/4 <> 10
Figura 5.2.2 I Relac.onal operators
Logical operators
KEY TERMS
Sometimes logical tests are more complicated ,han a simple Yes/No er
True/False answer. When tnat is the oase we can use logical operators.
The three logical operators that you need to knew about are AND, OR
and NOT. AND and OR are used to join togetr er two logical lests. NOT
Is put In front of a logical test lo reverse its meaning.
The next table shows the lhree logical operators.
Operator
Example
AND
(x) AND {y)
Both the statements x and y are lrue
OR
(x) OR (y)
NOT(x)
At leas1 one of the statemenls x and y is true
Stalemenl x is not true
NOT
Logical operators Logical
operators allow you to cor1bine
yes/no stalements, to give a
stalement I.Pat Is ei1her true or
false. Examples are: AND and
OR and NOT.
Meaning
1Nhere the letters x and y are shown, you would put a logical test.
Example: Wnal if a pupil has to ge, a mark above 49 in an exam AND a
mark above 29 in an essay to pass a course?
The slatement
(Exa.mMa.rk > 49) AND (ESSllJ'M a.rk > 29)
combines two logical tests using the logical operator AND. If both tests are
true then the whole expression is true. The studen'. has passed .
I' ACTIVITY
I
V\lrlte out in words 1he meaning of
eaoh lir.e of the table.
LINK
('~
Find out more about
All li'e possible 11vth values for
AND, OR and NOT are set out
ln 7.12.
Calculations
LEARNING OUTCOMES
In 5.3, you will learn how
spreadsheets are used 10
oarry out calculalions using
mathematical symbols, such as
addition ard subtraction.
Formula
If you want to perform a calculalion in a spreadsheet you use a formula. A
fcrmula is an equals sign followed by a calculation. A calculation uses the
arithmetic operators that you learned about In 5.2.
To enter a spreadsheet formula:
• select a spreadsheet cell
• enter the formula
• the result cf the formula will be displayed in t11e cell.
Figure 5.3.1 shows a very simple example. The user selected the cell 0 4
and entered the formula
=28/7
This formula uses the arit11metic operator /, which means 'divided by'.
The result of this calculation is 4.
••
Toe expression BOOMAS is used
i0 malhs to remind you of what
ordef mathematical operations
are carried oui In complex
calc,;latlons.
B-Brackets
0 - (power) Of
0- OivJde
M-Multiply
A-Add
S-Subtract
You mlgh1 have learned a different
version such as 'BIOMAS' or
'PEOMAS'. Any of these ,,nu
help you remember tne order
of calculation. Ask your math$
teacher for more information.
Look a1 Figure 5.3.1. You will see that the result appears In the cell. The
formula appears at the top of the screen in an area called the formula bar.
A
• •
I
~
C
-an.,..___ Trefo-rrula
0
I
The resv~ o'
,
,
Iha fo,..,u:a
:;::~ers "cne
Figure5,3.1
°'
fi11;tj - ------£ =Jl••
the user
en:ered Ir
cell D4
Formuas
'Power of'
In matns you sometimes wish to calcula'.e a number 'to the power of 2'
or '10 the power ol 6'. For example, 5 x 5 x 5 can be written as 5' or 'five
to lhe power of three'.
In spreadsheels, the symbol A is used to mean ·10 the power of' .
So to calculate 5' you would enter the formula
=5"3.
The following 1able shows some examples of lhis formula.
Calculation
Meaning
Spreadsheet formula
Result
5•
5 to the power of three
=5"3
125
102
20
10squared
=10"2
100
2 to tne power of 6
=2"6
64
Brackets
Brackets can be added 10 complex formulas. The calculation inside the
bracke1s Is carried out first This Is lhe same principle that you will have
learned in maths.
Cell references
So far you have looked at calculations that use arithmelic operalors and
numbers. But spreadsheets also allow you lo create calculations using
cell references instead of numbers.
A cell reference is the address of a cell. You can include a cell reference
In a formula by typing lhe cell address or by clicking on lne cell as you
enter a formula.
/ ACTIVITY
The spreadsheet software will:
1 Copy the simple spreadsheet
• lock in the cell
• get the number thal is in the cell
• use that number in the calculation.
Figure 5.3.2 shows a spreadsheet. There is a formula In cell 86
(=83+84). Toe formula contains lwo cell references (83 and 84).
The computer locks In tne cells, gels lhe two numbers (3 and 10) and
adds them together to give the resuli 13. This result is shown in cell 86.
..
,.c...~-
•
formJla wi'31 eel
.!...l C
A
10.,.-'•-
nterenoes
shown In Figure 5.3.2. Make
changes to the numbers in
cells 83 and 84 and see how
1he result In cell 86 changes
automatically.
2 Create a simple spreadsheet
that adds up the cost of five
Items on a shopping 11st. You
can make up whatever rtems
and costs you want. Use a
formula to add togetner the five
costs.
2
J t.ayfCNMftJOM
J
tluildffjJJS
10
•:I
I TQT"l.
1
Figure 5,3.2
I
1ij
I
Result of 10,.,.,va J
I Ce I references
Why use cell references?
There are tv10 advantages to using cell references instead of numbers in
your calculations.
• If you change the number in a cell that is used by a calculation then
the resuli will change automatically. This can save you a lol of time.
• On a spreadsheet you set out all the numbers you need for your
calculation. Each one is in a different cell. and there are explanatory
labels or headings. This makes h easier to read, to check and 10 share
your work.
LINK
Find out more about
Arithmetic operators: 5.2
Cell addresses: 5.1
Arithmetic functions: 5.L
%
Functions
What is a function?
LEARNING OUTCOMES
In 5.3, you learned about
formulas that t,Se arithmetic
operators. In 5.4, you will learn
aboUt functions that let you
carry out more oomphcated
calculations.
A function is a mathematical process that provides the answer to a
question. For example, 'what is the square root of 17?' Figure 5.4.1
shows a diagram of the operation of a function. A function can have
one or more inputs, but it always produces a single output.
Every spreadsheel function has a name that is is typed Into a cell. The
inputs to the function are typed in brackets al!er the function name. The
outpU'! of 1he function is displayed in the cell.
Example of a function: square root
Input
lnl)Vt
nput
A number 'squared ' is a number multiplied by ttself: 2 squared Is
2 x 2, 5 squared is 5 x 5 and so en.
The 'square rool' of a number makes that number when it is multiplied
by ttself.
FUNCTION
• The square root of 4 Is 2. That is because 2 x 2 ; 4.
• The square root of 25 is 5. That is because 5 x 5 ; 25.
It can be hard to work oUt square roots. Spreadsheets make It easy. The
funolion to calculate a square rco1 looks like this:
Outoct
Figure 5.4. 1
Ope·at on of a func'.,on
; SQRT(input)
The function begins with an equals sign, then the label SQRT, then
brackets. All spreadsheet functions look like this. Only the label is
different for each different function.
Where the word 'inpUt' is shown, you enter a number or a cell referel'ce.
The function
; SQRT(25)
will give you the square root of 25 - in other words, the answer 5. This
result is displayed In the cell where you entered the function.
The function
; SQRT(C4)
gives the square root of whatever number is in cell C4. If you change the
number in cell C4 then the 0U1put of the function also changes.
To Include a cell reference in a function you can either type the cell
address as letters and numbers or click on the cell while you are typing
the function.
Range function: SUM
•• •
Many funclions operate O'l a range of cells and produce a single cUtput.
You learned about ranges of cells in 5.1. A range 1s a connected block
of cells.
Tne mathemahcal symbol fer
'sum' is the Greek letter Sigma,
written !Ike this:
Figure 5.4.2 shows part of a spreadsneel. The range B2 to B6 contains
a sel of numbers. Cell B7 contains the function SUM. Sum is a
mathemalical term meaning 'add together'. The SUM function takes as
Input all the values in a range of cells and outputs the sum after adding
lhem all logether.
., .r-A
,
1
I
,.
dUM(ll-MI
....,.,.:....;:::::=:~--I
The SuM fuctQn
I
C
C:
20
1'
J
/ ACTIVITY I
77
,,.,•l-- ---7 '.t>e result of I
11)
I
The
••
Figure 5.4.2
Most spreadsi1ee1 soflware
systems include this symbol
on the tool bar at !he top of lne
scree'l. Click en tnis symbol as
a quick way to use the ·sum'
funellon.
function
1 Copy the simple spreadsheet
shown in Figure 5.4.2. Tes! all
1he functions mentioned on
1his page .
2 Make changes to the numbers
The SUM funct on
In the range and see how the
results of the functions alter.
Range functions
The next table shows the main functions tha11ake a range of cells as
Input and produce a single output. You can enter any range of cells as
lhe input. In the example here, lhe cell range B2 to B6 is shown, but any
range can be used.
Function
Example
Output
Explanation
Sum
=SUM(B2: B6)
134
Count
=COUNT(B2:B6)
5
Counts how many numbers there are in the range
Average
=AVERAGE(B2:B6)
26.8
\/\larks out the average (mean) of the range
Maximum
=MAX(B2:B6)
77
Finds the largest number in the range
Minimum
=MIN(B2:B6)
8
Finds the smallest number in the range
Adds up all the numbers in the range
More than one input
The function RANK takes tvvo inputs: a range of cells and a single
number. It tells you what the position of the nvmber ls in the range. That
is, if the number is the biggest in the range tt gives the number 1, tt tt is
the secorlcl biggest it gives the number 2, and so on.
Here Is an example of the RANK function:
=RANK(B2, B2:B6)
This function will lell you what rank the number in cell B2 has in the
range B2 to B6. The answer is 2 because 20 is the second biggest
number in the range.
LINK
%
Find out more about
Cell range: 5. 1
VLOOKUP function: 5.10
IF function: 5.11
•-
.
Formatting a
spreadsheet
What is displayed?
LEARNING OUTCOMES
On previo~s pages In this unit
you nave seen how to use
spreadsheet software 10 carry
out calculations. In 5.5, you
will learn now to use formattirg
commands to improve the
appearance of a spreadshee1.
You can enter a label, value, cell reference, formula or function into a
spreadsheet cell. What is displayed in the cell is not always the same as
what you type.
Type of
data
What you type Into a cell
What Is displayed In the cell
Label
Any set of characters
Exactly as typed, aligned to
the left
Value
Any number, can include a
decimal point
The value entered, aligned to
the right
Cell
Equals sign followed by the
reference address of another cell
The content of tne referenced
cell. If the value in the
referenced cell ls changed
then every cell that references
it is also changed
Formula
Equals sign followed by a
calculation
The result of tne calculation a value aligned to the righ1
Function
=FUNCTION(lnput)
The outpU1 of the function - a
The 'input' can be numbers value aligned to the right
or cell references
EXAM TIP
Rl!M.l"'-<bty thett .s.x:r
Text formatting
LAg6LS C! Yt etL,g~d to
th e Lef1:, Cl "'-d Nt..<.M6R.lC
The appearance of any cell can be altered usi,i.g text formatting.
Text formatting in a spreadsheet ls very similar to text formatting in a
word processing package. You can change the font, colour, size and
alignment of the characters.
VAL.I,{~ etye etLig~d to
tne Yig "1 t .
To change the text format, select the cell or cells ycu want to change
and select the text formatting options from the menu bar at the top of
the screen.
Number format
What you would see In
the cell
Number formatting
General (this is tne
defautt format)
028
Increase number of
decimal places 10 five
028000
The way that a value appears in a spreadsheet cell
can be changed by using number formatting. The
table shows some examples of how the appearance
of the value 0.28 can be changed.
Decrease number of
decimal places to one
0 .3
Percentage
28%
Currency
$0.28
'General' number format Is tne default, and ,his will be
used if you do not specify a different format.
Date formatting
=NOW()
The NOW function enters the current date and time into tne spreadsheet.
This is a func!ion that doesn't take any input values. Type this in any cell:
=NOWO
The cvrrent dale and time will be shown . The date and time will update
every time you carry out a calculation on the spreadshee'.. You can also
enter a date by typing tt in.
A range of date formais are available, wnich change the way that
the date is shown. Figure 5.5.1 shows the same date (22 July 2018)
formatted in several different ways.
8
22/07/2018
22July2018
22/07/18
22.7.18
221011201s 20:3ol
Figure 5.5.1
Date forfT'ats
Rows, columns and cells
You can change the appearance of the spreadsheet grid itself. You can
change the background colour or shading of the cells. You can also
change the colour and width of the borders between cells. This is similar
to the way you format the appearance of a table in a word processed
document. You can select a range of cells and format them. or you can
change the appearance of the whole spreadshee1.
You can make spreadsheet columns and rows larger and smaller by
clicking on the borders of the spreadsheet. You can then drag the
horizontal or vertical borders between columns and rows to change
their size.
You can also ifJSert new columns and rows into the spreadsheet:
these will appear as blank rows and columns inserted into the existing
spreadsheet.
ACTIVITY
You created a range of simple
spreadsheets in previous
activities. Now select and use
formatting features to enhance
the appearance of each of these
spreadsheets.
Use of formatting features
As you have seen in this section, tl1ere are many ways to change the
appearance of the elements of a spreadsheet.
When you are creating a spreadsheet, you should think about what type
of data are held on the spreadsheet and how they will be used. Your
formatting choices should make it easier to understand and use the
spreadsheet data.
For example:
• use suitable formats such as currency and percentage to make tt clear
what kind of data is used in the spreadshee'.
• main headings can be formatted with large bold text
• if there are cells where you want the user to enter new data these
could be emphasised using colour or other features
• tt a key result appears in a particular cell then make this cell bold or
give it a border.
LINK
Find out more about
Table formatting: 4.4
Functloos: 5.4
%
Copy and Paste 1
LEARNING OUTCOMES
You have learned about u$ing
COpy and Paste In word
processing and o:her software
applications. In 6.6 and 5.7, you
will leam now Copy and Paste
ca" be used to save time and
make spreadsheels more useful.
,.
I
l
I
I~
Fill
As well as using Copy and Paste from one cell to another, spreadsheets
allow you to copy the contems of a cell to all the cells below tt, or to the
right, wfih one simple action. This is called 'FIii down· or 'Fill right'.
Fill hanole
•
Figure 5.6.1
You can use the familiar Copy, Cut and Paste tools when working with
spreadsheets. Spreadsheet software lets you COpy and Paste labels,
values and other items such as formulas and functions.
'Fill' Is carried out using the 'Fill handle· at the bottom right of the
selected spreadsheet cell. Figure 5.6.1 shows the location of the Fill
handle. If you drag tne F,11 handle down, the content of the cell is copied
lo the cells below.
I
I
Copy and Paste
FJ,1 handle
Copying a formula
If you copy a formula to a new oell, using FIii or any other copy method,
1ne spreadsheet sohware will change any cell references in the formula
to fit the new location.
Here is an example. Figure 5.6.2 shows a spreadsheet that a teacher
created 10 store student marks in three tests. A formula has been
entered In cell F4 to add up the test marks of the first student.
Fo'!rula ,n~el F4
"
A
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.- ...
J
WW
s ltlllffl-;
••
Spreadsheet so'tware recognises
corrvnon data sequences. If you
erter a number, a month or a day
and Fill down, the software Will
continue 1he sequence. So, ~ YoU
start with a oell that hc;1s 'Monday·
in It, you will see 'Tuesday',
Wednesday', 'Thursday' In each
cell as you copy It.
This reature is called Auto-Fill.
I1 ""'""'
Youn•
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r... 1
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Figure 5.6.2
I Fo'f'l'ula to copy
The formula In oell F4 is C4+D4+E4. The result ol tnis formula Is 54.
The ieacher wants to carry out the same calculation for every studem.
So she copies the formula down lo the cells below. Figure 7.5.3 snows
the result of copying tre formula from cell F4 down to all the cells below.
In each row the formula changes so that the result ln each row is right for
1hat student.
The formula in cell F8 is C8+D8+E8. The result of 1his formula is 46. The
formula has changed as it is copied to a different row.
J "ormua In oel F8
rm
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,
• ~i..,
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Figure 5.6.3 l Formula a<cer oopylrg
Rel ative cell reference
If you copy a formula in1o a new cell. the cell references in the formula
will change.
• If you copy a fcrmula to a different row cf the spreadsheet then the
row numbers of the cell relerences will change.
• If you copy a formvla to a different column ot the spreadsheet tnen 1he
column leners in the cell references l'AII change.
• If you insert a new row or column into a spreadsheet, all tne relative
cell references are adjusted automatically so they still wor1<.
A cell reference that changes as It is copied is called a relative cell
reference. All cell references in all the formulas and functions of a
spreadsheet are relative cell references by default.
If you don't want a cell reference to change when it is copied. you need
1o use an absolute cell reference. You will learn more about absolute
cell references in 5.7.
ACTIVITY
1 Create a version of tne
spreadshee1 shown in
Figure 5.6.3. You can add
extra names and lest results to
1he lis1.
2 Enter a formula In cell F4 that
calcula1es the to1al marks tor
Kelly Bailey.
3 Copy this formula down 10
1he rows below. See how the
relative cell references change
In each row.
Usage
Rela1ive cell references are useful when you want 10 carry out 1he same
calculation many l imes. using different data. Adding up the s1uden1s' test
results was one example. Others are:
• adding up employee wages
• keeping s:ock records in a shop or warehouse
• calculating results from a series of scientific experiments.
Using a spreadshee1, you can set out the da1a. Typically, each se1 of
da1a is entered in a different spreadsheet row.
If you can work out the right formula to use in the first row of data, then
you can copy 1he formula down 10 all the olher rows. Because of relalive
cell references. the fcrmula will change In every row 10 give you the
correct result for the data in each row.
LINK
Find out more about
Copy and Paste: 4.1
Formulas: 5.3
C'~
Copy and Paste 2
LEARNING OUTCOMES
In 5.6, you learned about copying
formulas using relative oell
references. In 5. 7, you will learn
about olher ways :o use Copy
and Pas:e.
Absolute cell reference
In 5.6, you learned that relative cell references c'1ange wr en a formula ls
copied to a new cell.
If you don't want a cell reference to change when a formula is oopied,
you can tvrn it into an absolute cell reference. To do ihis you put a dollar
sign $ into the cell reference, in front of the column letter or row m.,mber.
Then it won't change.
86
is a relative cell
reference
Beth the column and 111e row oould change
Ht11e reference is copied to another row or
ootumn.
8$6
is an absolute cell
reference
The row number 6 is locked, and will no1
change Hthe formula is copied to another
row.
$B$6
is an absolute cell
reference
Bctn the column letter and the row number
are locked, and neither will change if the
formula is copied to another cell.
Using relative and absolute cell references
In the example spreadsheet shown in Figure 5.6.3, a teacher added up
tne total marks of students across three tests.
In Figure 5.7 .1, the teacher has made some changes to tne spreadsheet.
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I Spreadsheet wth new 'OW and pe·cen:age calcvlanon
The teacher has:
• inserted a new row at the top of the list (see row 3). This row sr ows
the marks available In each test. In cell F3 these are added up to give a
total - 75 marks altogelher.
• added a formula in cell G5 to calculate the percentage mark of the first
student. This is calculated by dMding her marks by the total marks
available. The formula is =F5/F3.
• changed the format of cell G5 10 percentage format This is an
example of using data formats 10 show the type of data a cell contains.
How absolute references help
In the formula that the teacher entered Into cell G5, the student's mark
(from cell F5} is divided by 1he total marks available (from cell F3}. You
can see this formula in Figure 5.7.1.
\Nhen the teacher copied this formula down to the rows below, the cell
reference for the student's mark changed. In row 6 it changed 10 F6, In
row 7 tt changed 10 F7, and so on. But the reference for the total marks
did not change when the formula was copied.
G1
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somome
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Figure 5.7 .2
I,
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0
f
,
r,.-1
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T111)
Toalmerb
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• Copy the formula to the cells
belcw tt.
:rs
81
tJ
n
24
2l
:rs
!J
u
21
u
.. ""
n
• Enter a formula In cell F3
to add up lhe total marks
available from tne :hree tests.
• Enter a formula In cell F5 to
work out the percentage score
of the first student.
• Amend the form.,la to make F3
an absolute cell reference.
21
,.
7$
• Insert a new row and add the
tolal marks per test as shown
In Figure 5.7.1.
7111
II
2S
Make changes 10 the
spreadsheet as shown in this
section:
• Format tnis figure to display as
a percentage.
22
l•
2S
If you completed the activity in
5.6, you have a spreadsheet mat
adds up the marks for the five
st\Jdents.
"'""
. ,,,.
2S
ACTIVITY
4fl 61~1
I Use of absolute cell references
The reason tne cell reference F3 did not cnange when It was copied was
because the teacher had turned tt into an absolute cell reference F$3. By
adding a $ sign, she made sure the cell reference would not change. You
can see this formula in Figure 5.7.2.
Other Copy and Paste options
When ycu Copy and Paste a formula, there are several Paste options.
LINK
• You can choose to Copy and Paste the formula, as in the example
shown in this section.
Find out more about
• Yov can choose 10 Copy and Paste the value only, not the formula (the
number is copied to the new cell).
• You can also choose whether or not to copy number formats and
other cell features.
Copy and Paste: 4.1
Formulas: 5 .3
Relative cell references: 5.6
%
Working with large
spreadsheets
LEARNING OUTCOMES
The Copy and Paste features
you nave learned about are
particularly useful wnh large
spreadsheets. By copying a
'ormula down to ma'ly different
rqws you can save a grea: deal
of time.
In 5.8, you WIii learn about some
other ways of working wltn very
large spreads"eets.
Freeze row s or columns
Freeze rows
Typically, a spreadsheei will have a row tha1 contains headings. The
headings explain wha1 information is in each column of the spreadsneet.
Figure 5.8.1 shows part of a large spreadsheet. It contains records of the
issue of customer discount cards from a chain of electrical stores. Row 3
contains the column headings.
,.
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0
(
l customer OIKount Card Records
l
)
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CwdflVfflNf' CVllol'MrM.lfflMMI
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Figure 5.8.1
t.oc,lloft
O.O• bIO/OlnOU N M J.O(Ol/lOU N.,.Pon
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IJ/tlh011 NW Pott
le/Ila/XII I a.y.,t•
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_..,
..,,...,_
..,,,,_
Ml"'411p,
..,.._
....._
...,._,.
I Top of a very large sp,aadsheet
A large spreadsheei is like any other big document. You don'1see 1he
l'ihole spreadsheet on the screen at any one time, jus1 part of tt. You can
scroll down, or use the arrow keys, to look through the spreadsheet.
The problem is tha1as yc<J scroll down the document you can no
longer see the headings In row 3. The spreadsheet becomes hard 10
understand.
To solve 1his problem spreadsheets have a freeze feature. This feature
lels you freeze or leek rows conlaining 1itles so 1hat they always appear
on screen. When you scroll down a page, the lilies do not disappear.
Figure 5.8.2 shows what this looks like.
A
I
C
ti
, Cunomer Discount card Records
'
t
2
1 CMd ftUmbt-t c,-,,, .... w,rn;aenit, Oililt:ft.MINI
lOGMion
2J/07/11JU
to50M<C°""""
,0
ll/07/lDII "4W Pon
101Jl>roct"
tasl .........
211'11/10U aay,,tftl
$l
,aJI~
27/lf1/10U -ICII
,as, Cjlfu6t
2'/07/,011 ..........
,aJJMJl/'17/2011 ........
.,
..,_,.Ide
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,.
Figure 5.8.2
I Freez ng head , gs
..,._i.,,,!!J
,.,,._
Ml:~ll•ps
Mr A.Ml f'Nfl
M!Ulh'il
.....,...,..o1oy
_.,..
.J
In Figure 5.8.2, 1he user has scrolled down to rows 49-54. But rows 1-3
can still be seen at 1he top of the screen. They are frozen, or looked, and
do not disappear when you scroll down.
Freez e columns
You can also freeze columns. For example, a college prolessor has a
large spreadshee1 wfth lots of information about his students. Wnen
he crea1ed the spreadshee1 he froze column A, which con1alns the
students' surnames. Whatever otner information he was looking at, he
could always see the student's name on t11e screen.
h is possible to freeze both rows and columns at tne same time.
Split windows
e
C
1 !eustomeaOIKount Clrd Records
A
2
en ...-
toO$ ••lw<D
0$.._d
I<
10/0lmu N
-1001 t•IOO<
1"1/lDIIN
U/OS/:ZOU I(•
Cu,t_, _
~· ~
A
I
3 Add at least 40 more rows 10
1he spreadsheet Each row
should have the information
about one book. Get
lnformo1tion on books from tne
school library, or other places
wnere 1here are lots of books.
?9{07/IOII
17/07/lDU -
,0,1 " " ' - -
1031 .,,....
Figure 5.8.3
position of the column
headings before you enter
1he information into 1he
spreadsheet.
2l/'07r,,,11
21/07/lOll Htw
10Sl Cltlemen
,...u ,..u
2 Freeze row 1 io lock the
C
!O!I .......
Shlirltt
In Column A, 'Book Ible'; in
Column 8, 'Author surname';
In Column C. 'Number of
pages·.
~!
. ~1, _
--·-
1 In row 1 of a spreac;Jshee1 add
the following column titles:
The dark line under row 3 shows that It is frozen.
3
ACTIVITY
'lJ/07/2011 Htw
H/07/)011,.._
~
$pl,! winoows
Another way to work wrth a large spreadsheet is to split the screen
into two or more 'windows'. Each window shows a different part of the
spreadsheet. You can scroll within each window and enter data into the
cells. Flgure 5.8.3 shows 1wo 'windows'. Each window snows part of the
large spreadsnee1 of customer discount records.
LINK
How to lock or split
Find out more about
In Excel, ,hese features are available in the 'View' tab. The 'Freeze
panes' iccn will freeze the first row or column cf the spreadsheei (or any
seleo!ed area). The 'Split' icon will spltt 1he spreadsheet into two or more
windows.
Using spreadsheets to store
records: 5.9
Database tables: 6.1
C\)
Sorting a spreadsheet
LEARNING OUTCOMES
In 5.9, you will learn about the
spreadsheet commands 1ha,
are used to sort informa:lon Into
alphabehcel or numerical order.
Records and fields
A key idea in the organisa!ion of data is the distinction between records
and fields.
• A record is all the information that is stored about a particular person
or thing. For example, a school will keep a record on each student.
• A field ls a particular item of information. For example, student name.
When an organised oolleclion of data is set out in a spreadsheet table,
each row stores a record and each column is a field.
The heading at the 1op of each column 1ells you wha1 information is
stored in that field. This is called 1r e field name.
Sorting
When you sort a spreadshee; table the records are sorted. Tney are
sorted in order of one field. You must choose which field 10 use 10 sort
1he dalabase.
The lwo mai'l ways of sorting are alphabetical order and numerical
order.
• If you sort using a field with labels in it, then alphabetical order is used.
• If you sort using a field with values In tt. then numerical order is used.
For example, a spreadsheet was made wtth records of all the books in
a library. Figure 5.9.1 shows 1he records sorted In order of author name.
Obviously, only a few of tne records can be seen.
•
A
•
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Figure 5.9.1
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...........
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I Sort oy author surnalT'e
Figure 5.9.2 shows the same spreadsheet sorted in order of tttle.
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0
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Sort
Slul
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Filter
~Advanced
Sort & FIiter
V,ri,I
Figure 5.9.3
Sort icon
T<>lslof
I Sort by 11:'8
Sort command
Figure 5.9.3 shows the 'Sort' Icon from Microsoft Excel. All types of
spreadsheet software offer sort facilities . Click on the 'Sort' icon to begin
sorting. After selecting 1he 'Sort' iccn, you choose which column (or 'ield)
1o use for soning.
/ ACTIVITY
The activity in 5.8 asked you
to create a spreadshee1 wilh
information about at least 40
t)ooks.
The defautt sort field is the first column In tne table. Often the first column
holds a code number that is unique 10 each record. This unique code is
useful for sorting or searching the table of records.
Sort 1his database in at leasl
two different orders and prim out
each version.
Primary and secondary sort field
You can sort by more than one field, called the primary and secondary
fields.
Reccrds are sorted first by 1he primary field, and then nthere 1s more than
one record with the same pnrnary fie'd, 1hey are sorted
using the secondary ~eld. Figure 5.9.4 shows a primary
"'
and a secondary sen field.
,.._ ,.__
For example, In a library 1here might be more tnan one
book by tne same aUihor, so books witn the same
avthor could then be sorted by title. In this case, 'avthor'
is 1he primary field and 'title' is the secondary field.
----
Figure 5.9.4
--
• -
-·-·
•
x
e ,. ___
...,
Pr,may and secondary SO'< fielcs
Ascending and descending order
As well as choosing the sort f,elds, you can choose to sort in ascending
or descending order.
• Ascending order means sorting in numerical order from 1 upwards (1 ,
2, 3 and so on) or in alphabetical order from A to Z.
• Descending order means sorting from larges! lo smallest values or
reverse alphabetical order (from Z to A).
Ascending order Is often the most useful sort order. where you want 10
put a fisl in alphabetical or numerical order.
Descending order is useful nyou want 10 bring 1he larges! numbers to the
1op of a spreadsheet !able, for example the heaviesl Items or 1he most
expensive purchases.
LINK
Find out more about
Records and fields: 6. 1
%
Extracting information
from a spreadsheet
LEARNING OUTCOMES
You have learned ,hat
spreadsheets can be very large
and contain a lot of iiTormation,
In 5.10, you w,11 lear'l some of
the methods that allow you 10
4nd 1Pa l<1tormatlo'l you wan: In a
large spreadsheet.
Find
'Nhen you are working with a large spreadsheet you can use the 'Find'
1un~ ion to search for any string or value. 11 works In tt:e same way as
the 'Find' command you have already practised in the section on word
processing (see 8.1). You enter a set o1 characters - perhaps a word,
number or phrase - and the cell pointer will move to the next cell vvhich
contains those characters.
To use the 'Find' command you do not need 10 have your spreadsheet
set out as a database with records In rows. It works witn any
spreadsheet layoU1.
Filter
The Filter command only works if you have a spreadsheet laid out with
reoords in rows, and fields in columns.
The Fitter command lets you see only those records that match a
particular criterion. II filters oU1 the rest.
EXAM TIP
Figure 5 .1 0 .1 shows an example. The spreadsheet contains the records
o1students in a school. Each student's name and class is shown, and
wt:ether they are male or female. The Filter command has been selected.
1Nhen the FIiter command Is selected, little arrows appear at the top of
eacn spreadsheet column, next to ,he field name.
.Sorti"'1! Qv,,ci fil.teYi"'-0
Q;e to~ics tl'lQt ofl:evc
give chfr.c"'-ltij i,,,_ tl'le
eKlliM.S. TA~e so""'-e ti""-e
to 1wt1cti.se tl'lese s~lls Qs
)'Qrt of 1:JDIA.Y Ytvi.s,ovc.
..
l
I
.. ,.,.
D
C
Parle School Puell records
2 . .pllmdo • -
• JiNNtmt
..
·-7- ·-- '~J
• NIU
S MU
e.11....,
. C'-
Ce tt1
IOI
Sl fflO!I
IOI
c..tb
Alltl'la
IOC
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lQA
IOA
f
•M
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-......,.
~
ff.~'•
Figure 5.10.1 1 F te- a·rows nexc to 'led names
KEV POINTS
A criterion is a test or standard
used to pick things out from a
group.
Tne plural Is criteria.
If you click on one o1 the arrows. a box opens which allows you to filter
using that field. For example, you might choose to show only female
students, or only studenls ln class 1OC. Figure 5 .1 0 .2 shows the Fitter
command being used to show only records o' male students.
Complex criteria
The fitter example in Figure 5.10.2 uses a simple crnerlon ('Male'), bvt
you can create a complex criterion by combining several filters usir,g
relational operators and logical operators (see 5 .2).
Figure 5.10.3 shows a complex filter that searches for records where the
'Age' field is grealer than 12 and less ,han 19.
1
A
I
C
O
Parle W-1 Pupil reco, ci.
l ',,.pUcock • S...,_.
y-
• _,
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• _,
---
1 """'
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•
ti io,,, ...
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p
seected as a
~rt~lcn
Figure 5.10.2
...
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II ...,,,..
J
ol$oloaAI>
..... >to• ~ ". . (Nr«ttr
UJe••·.... --•-"Chlr.a.t
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-
Use of filter to s~ect male srudents' records
. . ••
"' I [ .-J
Figure 5.10.3 Corrplex enter.on cornbnlng :wo firrens
Search functions
In 5.4, you learned that you can use spreadsheet functions such as SUM
to perform mathematical calculations. Spreadsheets also have functions
that can find and extract data from a table. One of the most useful dala
functions is VLOOKUP.
In 5.9, yet. learned that the first column of a spreadsheet data table is
o~en used to store a code. A unique code is given to each record. For
example. there might be w,10 stvdents in a school with !he same name.
but each one will have a unique stlJdent code. Almost all data storage
systems use codes for 1his reason.
The VLOOKUP function 1,ses the unique code to extract data from a
table. Tnis is how you use the VLOOKUP function:
=VLOOKIJP(code, range, column)
\Nhen entering the VLOOKUP function you enter your own code. range
and column information:
ACTIVITY
Add the following fields to your
spreadsheet with inlorma1ion
about 40 books:
• Insert a new column 1 and
enter a book code for each
book.
• Create a new field that says
whether each book is fiction or
non-fiction.
Now produce a filtered list that
shows only the non-fiction
books.
Code is the uniqlJe record code that you are searching for. In ,he table
in Figure 5.10.1, this will be one of the unique pupil codes, P103 for
example. This is usually a ceJI reference where you will define what you
are searching for.
Range is the range of the table you want to search. In Figure 5.10.1 ,he
table range is A3:E7.
Column The column er field that you want to extract from the table - for
example. you might want to see the sludent's surname. In Figure 5.1 O. 1,
'surname' Is stored in second column In tne table. So, you enter ,he
number 2.
Your VLOOl<UP will look like this: =VLOOKIJP(Cl4, A3:E7, 2)
VLOOKUP will only work properly if:
• your data is in a 1able
• the column on the left of the table contains unique codes
• the unique codes are sorted in ascending order.
LINK
%
Find out more about
Relational operators: 5.2
Logical opera1ors: 5.2
Finding text In a document: <1,5
Unique code field (Primary
Key): 6.2
IF function and multiple
worksheets
LEARNING OUTCOMES
In 5.11, you will learn abou:
lhe IF \.nctton, which works
like i he IF structure In Pascal
programming, You will also see
how a spreadsheet can include
several dl'ferent worksree1s so
!here Is room for more data and
calcula1ions.
IF
In 5.2, you learned abOUl conditional statements. Tnese have the
strvelure If... Then ... Else .... The commands wtthin the conditional
statement are only carried out IF a test is true or IF a test is false.
In a spreadsheei . the IF function has the same purpose.
In a spreadshee1, the IF func1icn has this s1ruc1ure:
: IF(logical test, value if true, value tt false)
Logical test
You learned about logical tests In 5.2.
Here is an example. Tnis will test whether the value In cell 82 is bigger
1han 12:
: IF(B2>t2 .. .
Here is another example. This will lest l"/~elher cell C7 contair s the label
'Fiction' :
: IF(C7: "Fiction" ...
Value if true, value if false
The next two parts of the function show wnich values lo display tt the
test Is true. or if the test is false. Only one of these values will display in
the cell that comains the IF func1ion.
Exam ple
Figure 5.11 .1 shows an example of an IF function.
The test mark of student Kelly Bailey is held in cell G5. Tne IF func1ion in
cell H5 is:
: IF(G5>75%, "Pass", "Fail' )
ft$
,_
I
-
•
I, at,(GS,,,S"
•
,._
..,__....,. .........,_
a
UM!,...,_....,._
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Figure 5.11.1
C
fd1
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•
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IS
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u
1J
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l ot.I t'Mrb • ICOI•
7)
. . . ..,.
u
I Example of IF fu'lct,on
"
•
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lot
11
ti•,,..
&I'< ....
61'6 , ..
This func1ion says IF the total mark gained by the student Is more than
75% then display the label 'Pass'. IF the total mark is 75% or less,
display the label 'Fall'.
Note: This IF function includes a cell reference. Because tt is a relative
cell reference, it can be copied to all the otr er rows and it will change
to give tne right result for each student. Learn more about relative cell
references in 5.6.
M ultiple worksheets
A spreaosheet file can contain many sheets of data. Each sheet Is called
a ' worksheet', A collec~on of worksheets is cal ed a ·workbook' ,
ACTIVITY
1 Copy the student spreadsheet
shown in Figure 5.11.1 ,
2 Include formulas to calculate
all tne values shown, Including
adding up the total marks and
calculating a percemage.
3 Add an IF function in cell HS as
shown here, and copy it down
to the cells below.
At the bottom of the spreadsheet you will see tabs linking to lhe ot11er
worksheets that are available. Figure 5.1 1.2 shows these tabs.
..•
1
J hlff!I. .
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-
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19
u
I
.
1•11 J
"un
u
n
lS
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u
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,
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Wa,ksneet tabs
Flgura 5.11.2
Wor-<Shee: taos: Sheet ' , Sheet2 and Sneet3
By right-clicking on any of these tabs you can:
• add or delete worksheets
• change the name of lhe wcrkstiee11o give ii an explanatory label.
Cell references
A big adVantage of using multiple worksheets in the same workbook is
that you can include cell references to cells in other workbooks.
A cell address tnat refers to a cell in another worksheet includes the
name of the worksheet plus an exclamation mark. Like this:
Sheel 1!A2
This means cell A2 on Sheet 1.
So, a normal formula might look like this:
=A4+B4 ... C4
A formula using data from several works11eets might look like this
= Sheet1 tA4+ Sheet2tA4+Sheet3lA4
Multiple worksheets are useful for keeping a record of sales. A separate
worksheet is used to record sales for each monlh. A summaiy sheet using
cell references to each monthly sneet can provide summary infcrmation.
LINK
Find out more about
Rela!lve cell references: 5.6
('~
Spreadsheet graphs
Which type of graph to choose?
LEARNING OUTCOMES
The type of graph to make depends on the type of data you want :o
show. Here are some general rules.
Gr.iphs .ire a way of showing
rn,me<ical da1? in a form 1h.i: is
easy to understand. As well .is
calculations vslng 'ormulas and
/unctions, spreadshee, sofrv>Jare
Is very useful for crea!lng
attr.ictive graphs. In 5.12. you will
learn how ~o create grap;-,s ~sing
spreadsheet softw.ire.
Bar chart If you are comparing different quantities or percentages then
a bar chart (somelimes called a histogram) is a good choice.
Line graph If you are showing how a value changed over lime then a
line graph is a good choice.
Pie chart If you are showing how a Iota/ is divided up then a pie chart is
a good choice.
Some studems make the mistake of using pie charts for all graphing
needs . In fact, pie chans are the least useful graph type.
Creating a graph
1
..
•
Population of carlbbean nallOfts
1 ... , • Mlnlnlqw
• :19.SlO
,
~
JU.lll
6
ldftldld_, ,.....
17),SJO
IOC.IJ7
1.ffl,CIDO
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I Puctt'10 "1<0
1.11,,000
,
10.0ll.CIOO
Htijl
,o _ia,,,_.,...
11 CMN
FigureS.12.1
t~"2.000
IO,OI0l1,lOC,OOO
Datalorgraphshown n Fgure5. 12.2
Before ycu create a graph your data must be set out
clearly on the spreadsheet If 1hey are not set out
clearly and carefully then the graph might be hard to
create, or even incorreci.
As a guideline, have the values you want to use In
cells that are arranged in a row or column. Each cell
should be clearly labelled. The label should say what
the value is.
Figure 5.12 .1 shows an example of some da1a set
out in a suhable form on a spreadsheet. h shows the
population of the ten biggest islands in the Caribbean
region. Each value ls clearly labelled and the data are
sorted into order.
To create a graph. you would select the data from cell A2 to 811 and
then choose a suitable graph type. As this graph will be comparing
different quantities, a bar chart is most surtable.
Changing graph features
Figure 5 .1 2.2 shows the basic bar cnart that was created using 1he data
In Figure 5.12.1 .
A horizontal bar chart has been chosen, because this gives more room
for the labels. If labels are short you can use vertical bars instead.
This graph shows tne default appearance of a bar chart, before the user
has changed any graph features.
Jtnkl
JIIIIIIIII
■ SedHl
Tnn!d, d tnd TOobero : Guye Ill
MiUtlnlqu~
•
1.
..- .. J
8frbado$ ' '-----'---------!
o
Figura 5.12.2
10,0t'O,OOO
),000,Q>O
lS,(IQ),000
IPlan graph witn default 'ea:ures
The user decides lo make the following changes.
• Legend (or Key) The legend or key of a graph explains the meaning
of the different colours used in the graph. Differenl colours are used to
distinguish different sets of dala. In this graph there Is only one colour.
The legend nas only one enlry called 'series 1'. A legend is nol needed
in this graph, so it was deleted.
• Title Tne user added a graph title 10 explain what the graph showed.
• Axis title The x- and y-axes are :he two lines to lhe bo1tom and left of
the graph. The user added an x-axis tttle al the bottom of the graph to
explain what the numbers meant.
• Format Tr.e user changed the colour format to make the graph more
attractive.
Figure 5.1 2.3 shows 1he finis11ed graph whh all these changes.
The ten largest nations In the carlbbean
•
............
trlflldod..-1' : ;
Guy,"'
,, ACTIVITY
•
1
I
1 Copy the spreadsheet data
shown In Figure 5.1 2.1.
~
2 Create a graph from these
~
1\1.tnlt\lqut
)t
91hll1'11
II
ll&tt,oclol
•
0
I
data, using suitable fealures.
3 Do some research to find 0 1.11
•,IOQ.Cll:IO
1,00QOOO
............. t.... _,,,..,
Figure 5.12.3 I Gra,oh with i11proveo feat\Jres
12.Dm.000
how the population of your
country or town has changed
over the years. Create a line
graph to show this changing
valve.
Import to a spreadsheet
LEARNING OUTCOMES
If you copy an ltern frorn one
type of software Into arother,
this Is called lrrportirg. In 5.13,
you w,11 see how you can mport
,ables a'ld graphics pceoared ,n
otner softvvare packages Into a
spreadsi,eet
Interoperability
If two software packages can share data, they are 'imeroperable'.
Nowadays, most major software packages can exchange data, even if
they are made by different companies. Th s ,s because users Ike to buy
new software tnal works well with the software they a'.ready own.
Many manufacturers create sets of software packages that all work
well together. Tnis is sometimes called a software suite. Microsoft Excel
is part of :he Microsoft Office software sutte. That means it can easily
exchange data wtth MS Vvord ar,d other software applications.
There are also common software standards that mean tha'. tt is often qutte
easy to just Copy and Paste 11ems from one package 10 anolher.
Insert items
....
..... ,.._,
....
,... .........
.,.. ...,,_
... .. °""""'
,.
••
Figure 5.13.1
.
Insert o.o:ons
Figure 5.1 3.1 shows a typical insert menu on a spreadsheet. The figure
shows some of the items that you can insert into a spreadsheet.
As well as using the features on the 'Insert' menu it is often possible to
simply cut and paste images. text, or numbers from other documents
and files into a spreadshee1.
Images and Clip art
ACTIVITY
You have learned about pulling graphics such as pictures and Clip art
Into word processed documents (see 4.4) and presentations. You do this
In exactly the same way when you are using spreadsheet software.
Take one of the spreadsheets you
have created and Improve the
formal ting.
Once it has been inserted, the image or otr er object can be resized or
moved.
Add an image, such as Clip art,
to the spreadsheet. Make it a
suitable size and place it In a
suitable locailo'l.
Tables
If you have prepared a table In a word processed document, you might
wish lo import tt inlo a spreadshee1. For example. ihe table might Include
numerical data, and you want to carry OUl some calculalioris.
Copy and Paste is a simple way to import a 1able into a spreadshee1. To
do this:
• cut or copy the table from the original document
• open spreadsheet software
• move 1he cell pointer to any cell in the spreadsheet
• use the 'Paste' command to place 1he table in the spreadshee1.
The software will automatically spread the 1able across however many
columns and rows It needs.
Column width
You might need to increase the width of the spreadsheet colomns to fit tne
dala. tt tr e con1ents are toe big to frt In the column you w,11 see symbols
like this: ####ff. In 1h15 case, you need to make the columns wider.
Formatting
In 5.5, you learned how you could improve the
appearance of a spreadshee1 by adding borders, shading
and different text styles. Cnoices about colours, layout,
fo~t and other features should be made by 1hinking about
whal '.he spreadsheet is to be used for.
Figure 5.1 3.2 shows 1he studenl test resut spreadsnee1,
with Improvements to the formatting and an imported
image.
•
•
-- ···-- -
:A
C
rOfkkhOol ...........
.
t
.." ... -
"~ ... ,..,, , , . , u
, ...,._..-...,.
,.., "• 'n
.."
"•'
c....
~
....
Figure 5.13.2
Templates
I
'
'
, __ ,.u.
.• .,.•'...
u
.." •
Soreadsheet showing 'oITT'atting and an
l11ported Image
You can also use ready-made templates tha1 have struciure, formatting
and layout already designed for you. These are often provided with
spreadsheet software. Figure 5.13.3 shows a templale fer a spreadsnee1
1o record your exercise routine.
In Excel, if you select 'New' on lhe File tab you will see a wide range of
1emplal es offered by Microsoft. Similar templates are available for other
spreadsheet softvvare. You could also use 1emplates crea1ed by your
1eacher or other people. More 1emplates are available online.
---
-
LINK
%
Find out more about
Adding graphics to documents:
4.L
Spreads\1ee1 formatting: 5.5
Figura 5.13.3
Spreadsheet temp ate
Pivot tables
What is a pivot table?
LEARNING OUTCOMES
In 5.14, you w I learr wnat a pivot
:able is ard now it can be used to
reorgan se da~a
Scmetimes, you may have a large spreadsheet that contains a huge
amcunt of data. It might be a large suNey of how :he population of a
coun:ry Intends to vote in an election.
The data are valuable but only beccme uselul when people can use
them to answer ques!ions. A political party may want to know how
well they are appealing to young voters, for example. A pivot table
is a spreadsheet tool that is designed to help people get answers to
questions like these quickly and easily.
KEY POINTS
Pivot table A special kind
of spreadsneet t.ible !hc;1t
s.ir1manses tne da:a In another
large and sometimes complex
claia :able.
Pivot chart The same as a pNot
table but the summary Is outpv:
i"l graphical form as charts or
graphs,
Voting survey example
A company has carried out a survey on voting intentions of people as
a general election is approaching. Three parties will take part in the
election: Lab, Ub and Con. Tne voting takes place in four regions, North,
South, East and West. The suNey also asked the age of each voter. A
small part of the suNey dala is shown in Figure 5.14. 1.
1 Name
Sex
Region
2 Marl< Smith
Vote
M
East
4S
M
West
F
East
M
N orth
Tc create a pNot chart, you select
the 'Pivct chart' buttcn in the
lnser: tab Instead of tile 'Pivot
table' bviton.
~ Leroy MacDonald
6 Donovan Williams
M
North
23
56
34
37
7 Aysha Whitmore
F
South
78
Con
8
F
w est
9 ! N icole Davis
F
East
34
23
Work in the same way as you
would to cre<31e a pivot table. Tne
oi.i1put will be a chart.
10 campbell Facey
M
56
11 Donna Silver
12 Shereen Hamilton
F
F
East
North
South
Lab
Lab
Lib
Con
Lab
13 Fabian Morris
M
West
14 JDevlin Brown
M
North
42
27
- ------.
-·---·-----·
------ -
-· -- -· --'
c ....- - -
Lauren Campbell
Figura 5.14.1
114
Con
Lib
lab
Lib
I Voter survey
The results have been given to the three pol~ical panies. The examples
thal follow show how a pivot table could help lhem 10 understand the
data.
'
Creating a pivot table
To create a pivot table in Microsoft Excel:
• Highlight the data table.
Create a pivot taole
65
Lib
•
.,.._
Figure 5.14.2
34
I
Lab
lab
3 David Jones
4 Ann Wilson
._
I
Age
• Select pivot tabla in the 'Insert' tab.
Using a pivot table
Once the pivot table has been created, a 'Pivot table fields' box is shown
on screen. This box. shown In Figure 5.14.3, allows you to lell 1he pivo1
table wha1 da1a lo display.
•
Pivo1Table Fields
-
"
0.
Qwe«,...td... ,.,..;.
JJ
oOi<o
~
Id ......
aria ...
v...
~
•
Ol .. t.eiJllw..M., ... .....,
Figure 5.14.3
I P,vottat>lefelds box
The 'Pivot table fields' box contains a lis1 of field names (for example,
Name, Age). Underneath are four areas where those field names can be
dragged: Filters, Columns, Rows and Values.
In this example, the 'Region' field has been dragged into 1ne Columns
box, 'Vo'.e' inio the Rows box and 'Vote', again, Into tne Values box.
1Nha1 1his will show is how people in each region intend to vole. The
result is shown in Figure 5.14.4.
I
!eountof Voteleo1 •
Row labels • East North South W est Grand Total
Con
12
8
214
36
Lab
Lib
22
6
40
1.2
10
30
6
2
10
16
6
36
56
2A
116
/ ACTIVITY ~
Crea:e a da1a 1able using the
formal shown in Flgure 5.14.1.
Work with others in your class
to creaie a file with at least 100
records.
, Create a pivot table and use
It to recrea1e as closely as
you can 1he reports In Figures
5.14.4 and 5.1 4.5.
2 Create a new 1able that shows
1he percentage of male and
female voters whO will vote for
each of 1he three parties.
,I
Figure 5.14.4 I Voting tJy regon
Formatting a pivot table
The example in Figure 5.14.4 shows how people in three age groups say
they will vote. While this 1able looks quite different to 5.1 4.4, it needs only
three simple changes.
1 Age replaces region in the columns box
C...ofYoe• ~
·
. . . &a-at • . . .
2 TI1e group function was used 10 create the age ranges
3 Data format is changed 10 show percentages.
These changes tell you quickly that 1re Lab Party is most popular with
young and old voters, and the Lib and Con parties are mos1 popular l'Ath
middle-aged voters.
40-.ff
...
:~
11.-...- ....,. ........
....
IO,OCl"I).. . . . .....,.
Ul:I
0r..-,...
G,.....
f.
nMW
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,,.... " ·" " \1.11'1
lll.lifllJC
tOUft ~ ......
•. . . .
Figure 5.1 4,5
IVot,ng by age
SECTION 1: Multlple-cholce questions
1 l<l the following spreadsheet formula, which
calcolation is carried cv1 'irSl?
=(B2+B3)/4T2
a 4+2
b B3/4
c B2+B3
d (B2+B3)/6
5 tf the formula in cell F2 is copied down to cell F3
1<1/11at 'ormula will appear In cell F3?
a =SUM(B2:E5)
b =SUM(F2:F5)
c =SUM(B3:E3)
d =SUM(B5:E5)
2 In the following spreadsheet formula what is
using a graphical representation. Which of the
following would be most appropriate to display
ihe total score for each student?
a Bar chart
b Pie chart
c Line cnart
d Doughnutcnart
A1 :A6?
=SUM(A1:A6)
a A function
b A cell ra ,ge
c A cell reference
d A formula
0
3 Cells B2 to B11 in a spreadsheet contain 1he
number of sandwiches sold by tr,e cafeteria
each day for 1he past ten days. Which formula,
pl?c(ld In cell B12, wovld calculate the average
number of sandwicnes sold for the penod?
a =Sum(B2:B11)
b =B2+B11/10
C =Average(B12)
d =Average(B2:B11)
Use the spreadsheet below to answer
Oues!ions 4-6.
A
B
C
(l)
ti
1
.2
(fJ
Tom Hinks
3 Brian Harris
4 Jael Marcelle
5 Anischa
Chung
2
C
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1n
E
a
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:S g>
<fl
(l)
"' w (.) a.
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18
17
19
15
12
13
18
19
F
-i9ra
15 19 =SUM(B2:E2)
17 20
15 14
16 19
6
4 \1\/hich cell contains the Chemistry mark for Brii;lr
Harris?
a D3
b D1
c A3
d A5
6 The 1eacher wants to display the students' data
7 Spreadsheet formulas can lnclt,Jde ,ibsotute or
relative cell references. Wnal is special about an
absolute cell reference?
a Absoh.i1e references canno: Change their forma:
b Absolute references do not change when
1hey are copied to a new cell
c Only absolute references are shown as cell
addresses
d Only absolute references can be included l'l
spreadsree1 formulas
8 Whal Is tne difference In the way values and
labels are displayed In a spreadsheet cell?
a labels only cor,teln letters, values only
contain numbers
b Labels are left-justified, values are rig,,t-justified
c Labels are In bold text, values are In normal text
d Labels are indented, values are calculated
9 Wha1 is tne term for copying the contents of a
cell into the cells below it?
a FIii down
b Relative reference
c Spreadsl'eet function
d Column lock
10 The value 0.1 is formatted as a pe,-centage. How
does it app~r In the cell?
~
1%
/ Further practice questions
1
b O. %
and examples can be found at
c 100% www.oxfordsecondary.
d 10%
ccm/9780198437215
a
\t 1'_
•
SECTION 2: Structured questions
1 Ouesllon 1 refers to the following ei<ample spreadsheet.
A
B
1
Tax
17.5%
2
Duty
24%
D
C
3
4
Make of Vehicle
Net Cost
Tax payable
i-5---;-Tc--o_y_ot_a_C_o_ro_il_a_ _-tS2
-◊
-,0
-0
-0-.0
-0_ ___,
Duty payable
a What is the cell reference o' tile highlighted cell?
b \/Vhlch cell contains the percent.ige tax to be pi;ild on car purchases?
c What IS the formula to muttiply the cost of the car by the percentage tax rate?
d \lvhat formatting ls used for the data in cell B5?
2 Question 2 refers to the following example spreadsheet showing a family's budget for the first quarter of the
year.
A
B
C
D
E
1
Family Budget
January
February
March
Total
2
Income
3
Salary
15,000.00
15,000.00
15,000.00
4
Commission
4,000.00
5,400.00
4,200.00
5
To:al Income
6
Expenses
7
Electricity
380.00
450.00
41 0.90
8
Travel
500.00
475.00
535.90
9
Groceries
1,200.00
1,325.00
1,1 50.00
10
To:al Expenses
11
Net profit/loss
a \lvhat formula should appear In E3 to caloulate the total salary for the quaner?
b What cell would you copy this form.,.la Into to calcula,e the total commission for the quarter?
c \lvhat form" la should appear In E5 to calcula!e the total income for the quarter (salary plus
commission)?
d In what cell snould 11-,e total expenses 'or January appear? Wnat formula would be shown In ihis cell?
e \lvhat cells would you copy this 'ormula Into to calculate expenditure tor February and March? What
formulas would appear in these cells?
f Vvhat fon'1ula would you enter In cell E11, and v>/llat does it calculate?
Further practice questions
and examples can be lound at
ww1N.oxfordseocndary.
com/978019843721 5
Database terms
LEARNING OUTCOMES
In 6.1, yoi.l will learn some of
the most tmportan: ierms tha1
you need 10 understand when
working with databases.
In Unit 6, you will learn about the software tha1 is used 10 create and
work with databases. Databases are large stores of information, and the
use of databases is one of the more complex ways in which computers
are used in tne modern world.
Al the end of this unit are some practice exam-style questions.
Database
A database is a large collection of data in a computer file. The data are
held in a structured form so It is easy 10 find the information you need.
A daiabase is typically made up of one or more tables.
KEY POINTS
Entity An entity Is anything you
want to store i'1'orma11on about.
An item, a place, a person or even
an event can be an 'entity' .
Attribute An entity has
attribvtes. These are tre 1a<1-s yoo
know about 1he entity.
Use 1he term atlnbvte when
referring 10 'acts about the entity.
3 00231
4 00232
5 'oo233
6 'oo234
1 roons
In the unit on spreadsheets you saw how data can be stored in a simple
table (see 5 .9).
The rows of the table are data records. Each record stores alt the
information about a particular item or person (called an 'enttty' - see Key
Points box).
The columns of the 1able are data f ields. Each field stores a single Item
of information (called an ·attribute' - see Key Points box).
Figure 6.1.1 illustrates 1hese conoep1s.
8
A
1 Ubrary Code
2 '00230
Table
Title
Anna Karenina
War and Peace
Les Miserables
Crime and Punishment
MobyOlck
Tevye the Milkman
One record: al tt,e n'o
abou· as ngle err.ty
Figure 6.1.1
A taoe showng a record (ye low) and a f.elo (o,ue)
C
0
Author Surname Author first name
Tolsto
Leo
Hugo
Dostoevsky
Melville
Aleichem
Leo
Victor
Fyodor
Herman
Sholem
One field: a sng<1 l:Em of
nforrratlon aoeut a entt es
Record
A record stores all the information about a single entity. Here are some
key facts about records.
• In a typical database table a record is shown as a single row of
the table.
• Every record in the table l1as the same fields In the same order.
• A record is sometimes called a tuple in computer jargon.
Field
A field Slores a single piece of information, also called an attribute.
In a typical database table, a field Is shown as a single column of
the table.
• Every field has a name; for example, in Figure 6, 1.1 , the highlighted
field Is called 'Author Surname'. The field name appears at the top of
the column.
• Every field has a size (or wid1h). This shows how much information can
be stored in that field.
• Every field has a data type.
Data types
The computer represents dala using digital codes such as ASCII. The
field type tells the computer what type of data is stored in the field, and
hence what type of code should be used to represen1 the data.
, ACTIVITY
Here are the main types of field.
• Numeric fields that store number values.
• Text fields that Siore characters. These are also called alphanumeric
fields as the characters that are stored can be letters of the alphabet
or numbers.
• Logical fields that store Yes/No values.
Other field lypes that are available include:
• date and lime fields
• hyper/inks to ether files, documents or internet addresses
• currency fields that store money values.
Key Fields
Every record in the database must have an attribute that is unique.
That is so you can tell that reoord apart from all the other records in the
database. This field is called the Key Field or Primary Key.
The Primary Key is oflen a code number that identtties each entity in the
database. In a school, students might have a code number 1hat appears
on a school card that they carry.
Find out more aboU1 Key Fields in 6.2.
I
A garage sells used cars. They
decide to create a database to
keep records of all these cars:
• VVha1 are the entities that this
da,abase stores information
about?
• Wnat are the attributes that
need to be recorded for each
entity?
• Wnat would you use as a
Primary Key field for this
database?
LINK
Find out more about
Spreaclshee1 data tables: 5.9
Key fields: 6.2
%
Use of databases
LEARNING OUTCOMES
In 6.2, you will learn about
lhe reasons 11'.at people use
databases. Dalabases are
designect to make lnfotma:ion
rnore ...seful and easy to use. The
vse of a Key Field helps make a
da1abase easier ;o use.
What are databases for?
You have learned 1hal a database is a store of information. But why
store facts In a da1abase? \/Vhy no1just type them into a document?
The features of dalabases are designed 10 make them more useful than
ordinary documen1s.
Here are some of the reasons why databases are useful.
• Standardisation Every record in a database has the same s1ruc1ure.
This means the da1abase user knows what information is held, and in
what form.
• Fast retrieval The way ,he informaiion is organised makes it easy for
the computer to find ttems of data in the database.
• Large size You can s1ore thol>Sands of records in a da1abase, and still
find the ones you want.
• Muttiple views You can produce many different useful outp.rts from a
database, in different orders, with different records or fields. Find more
about 0U1puts in 6.7.
Ad hoc q uery
An 'ad hoc' query is an unplanned or 'once only' question (see Key
Points box). Luckily you can find any kind of data in the database. For
example, If you have a library database you might decide 10 find out
'vs/nal was the book borrowed most often in 2018' or 'who has 1r.e most
overdue books'. Because l he database is se1 up In a structured way, you
can find the answer to unusual 'ad hoc' questions like these.
Database design principles
Database design must take into account a number of principles, for
example:
• there must be a way to Identify every record In ,he database, so tha1
the user can find informaiion
• data must be s1ored In a s1andard way throughout the da1abase
KEY POINTS
• each ttem of data should be stored once only.
Ad hoc This Is a Laiin phrase
To help identify and find every record In 1tle da,abase, a Key is used.
!hat literally r1eans 'for this',
11 is used nowadays to mean 'for
just this once' or 'one 11me only'.
In database work an <1,d hoc
query Is a new unplanned query,
lhat mig>it orly be l!c5ked once.
Use of identifying keys
There mus1 be some way to distinguish each record from all the other
records in the database. Fields such as 'Name' or 'Da!e of birth' are not
always unique. For example, a school might have more than one studen1
with the same name. For this reason it is necessary to have a Key Field
1ha1 is differen1 for every record in the database.
There are a number of types of Key. These are explained here.
Primary Key
Most database tables include a Primary Key field that stores a unique
value. The Primary Key is often a cede number that identifies each entity
in :he database. In a school, s1udents might have a 'student number'
that appears on a school card that they carry.
The Primary Key is usually the first field in the table.
Alternate Key
If there are other fields as well as tne Primary Key field that could be
used for the same purpose, these are called Alterna:e Key fields.
Composite Key
Sometimes a database designer decides to do wtthout a Primary Key
and uses a Compost e Key instead. A Composite Key is made by taking
values from more than one field 10 find a uniq\le way of Identifying each
record.
Candidate Keys
Together, all these keys: the Primary Key, Composite Keys and Altemale
Keys of the database are called 'Candidate Keys'. They are all possible
ways of identifying the records in the database.
Other types of Key
Some Key Fields are used for other purposes in a database. Here are
two examples:
Secondary Key
As well as the Candidate Keys, a database designer might define a
Secondary Key. This is a field that Is not necessarily unique for each
record in the database, but is very useful when you need to find a record.
It might be used 1o sort or reorder the database.
LINK
Foreign Key
Relational databases: 6.3
Foreign Keys are keys 1hai are used 10 link together different tables In a
relational database. Find out more about Foreign Keys in 6.3.
Database outpu;s: 6.7
%
Find out more about
ACTIVITY
A scientist is testing new fertilisers by growing
seedlings and measuring their growth.
He stores 1he information in a database. Each record
in 1he database stores iriformation aboUl a single
seedling. The attributes (fields) are:
• the species of plant
• the type of fertiliser used
• the size of the seedling on 1he firs! day of tne test
(in om)
• the size of ,he seedling on 1he last day of the test
(in om).
Now answer these questions:
1 \1\/hy should the scientist give each seedling an
identifying code?
2 What oU'ler Information might be useful to record
in the database. as well as the fields mentioned
here?
3 For each field in the database (Including new
ones you thought of for question 2) suggest a
field name and a suitable da1a type.
Relational databases
LEARNING OUTCOMES
So lar In this unt you have
learned about databases with
one table. But database software
lets you create databases that
have several di7ferent tables i0
them, connected by retatlo11Si'ips
between l he tables, Tris type
of database Is called a relational
database,
Good database design
A principle of good design is that a table should hold information about
only one type of entity. All the records in one table have exactly the same
slruclure and are made up of the same fields. Each record in the table
stores Information about a different entity, but all the enttties are ol the
same type.
Another principle ol good database design is that each piece of
information should be stored only once in the database. It is easy to see
why: entering the same piece of Information in several places is a waste
of lime and there is more chance to make a mistake.
If you put these two principles together then you can see that most
databases will need mere than one table.
Example
In planning a database you must decide which types of entities you need
to store Information about. Here Is an example. A library database needs
to store Information about three types of entity:
• objects: the books in the library
• people: the library members
• events: v,l hen a member borrows a book.
If you were keeping records by hand you might write something like this.
Thurs 10th March:
1 O.im Kim Brown, clase 2C, borrowed i'\nne of Green Gable$'.
1Oam Kim Brown, class 2C, borrowed 'Little Women'.
1 0:05 John Lord, class 2 E. borrowed 'Physics etudy guide',
10:15 Stuart Hyam, class 6A, borrowed 'History of the Amerlc.is'.
There Is a lot of repetttion in tnis system, arid many chances that
mistakes will be made.
By contrast, in a computer database you store all the information about
library members in one table. This information Is entered only once l'ihen the member joins 1he library.
M ember code
Surname
First name
Class
Date Joined
M0201
Brown
Kim
M 0202
Cooper
Adam
M0203
Talbot
Robert
2C
2C
2C
1/9/09
1/9/09
1/9/09
lnforma1ion aboU1 books is in another table. A new record is crea:ed
every time a new book ls added to the library.
I
122
Book code
Book title
Author name Date added
B8078
Anne of Green Gables
Montgomery
1213/09
B8079
History of the Americas
Dos Santos
1213/09
B8080
Workbook of Mechanics
Tayburn
13/3/09
,. ACTIVITY
Each table has a Key Field: a code that uniquely references each record
in the table. 11 is the first field in each table.
The record of a book beJng borrowed goes into a third 'transaction' table
like this.
~--
Date
Time
Manberoode
Bookcode
T010011
10/3/11
10:00
M0201
B8078
T010012
10/3/11
10 :00
M0201
B9900
T010013
10/3/11
10 :05
M0455
B0750
I
A co-operative store offers
its customers a membership
card with a customer code
on It. Every time a customer
makes a purchase, delails of
that purchase are recorded. Al
the end of the year. customers
recerve a dividend based on the
amount they have spent.
• Whal tables would you have in
the database?
• Show what the table storing
purchase records mignl look
like.
'Transaction code' is the Key Field of this table.
• Describe the relationships
between 1he tables in this
database.
Relations between tables
Instead of recording all the information aboU1 the member and the
book every time a book is borrowed, the librarian only has to record
the member code and the book code. Using just the code is enough,
because each code links back 10 a unique record, which has all the
other details that you might need.
The member code and book code are Foreign Keys in the transaction
table (see 6.2). They are Primary Key fields brought into another table to
make a link between 1he two tables.
One-to-many
Each use of a Foreign Key makes a link
between tables.
• Each member might borrow from the
library on many different occas.ons
over the years. This means the same
member code might be used n several
different p'aces In the transaction
table. Thcs is called a one-to-many
re'ationship. One member Inks to many
transactions.
• Each book might be borrowed many
times, so once again, there Is a oneto-many relationship.
One-10-many relationship Is the most
common way of linking tables together
in a database.
Me-nbe-shlp table
Merrbe· code
Other member
details
Merrbe• code
Book code
Dateanotime
Booktaoe
Sook code
Other boo<
detais
Transaction iab;e
Figure 6.3.1
Use o' Foregn Keys to ma¼e relaionsh os be~.veen tat:'es
LINK
Find out more about
Use of Key Fields: 6.2
Input to a database: 6.5
%
Creating and amending
a database
LEARNING OUTCOMES
There are ma"Y different software
systems available that allow you
to work witn databases. In 6.4,
you will learn about how software
is used to set 1,,p a new database
and to 1'lake charges to the
structure o' a database.
DBMS
The software ,hat oontrols a database is called a DBMS. This stands for
Database Management System. There is no standard appearance or
style for DBMS software applications. However, the basic features that
they offer are the same.
Types of DBMS
You have learned about relational databases. but there are otner types,
including hierarchical and networked databases. Relational dalabases
are the most commor1 type used nowadays.
Relational DBMS
MySQL is an ope'1 soorce
da'.abase system. It is used to
run (or contribute to) some of the
most popular websrtes on the
internet, including Flickr, YouTube,
Wikipedia and Facebook.
A widely used relational DBMS is Microsoft Access. Many other database
systems are available, including MySQL and Orac'e, for example. Many
of these systems are des•gned for expert programmers and are typically
used to handle very la•ge co lect ons of data.
See the database structure
In Microsoft Access, there is more than one way to look at the database
structure. These different ways of looking at the database are called
vievvs'.
1
• Dalasnee1view: This lets you look at the database as a table, set
out in oolvmns and rows like a spreadsheet. See Figure 6.4.1 for the
'Datasheet view· of a student reoord table, showing t,vo reoords.
• Design view: This lets you look at a list of all the fields in the table. with
the data type of each field. See Flgure 6.4.2 for tne 'Design view' of
the same student record table.
::1 ••··
"
•
Figure 6.4.1
~'•""°' •
• MonM.PflOn •
QW)Jl3ll
~
~ ~ c : o r t Ollil6tt
..,.n,m
E"f'nit4.\0dtm
, . , ~ _. .,
Acfiek'9;s
• <'ltttoAdd
!>)'11ffl1"f!Of
IOld~
Datasheet V1f'l'N
::i as,
0tt1Type
.AU!-bo<
"''".·:.::i------'..'
finl:Hlr'I•
Tm
t,.llMIIAdch.u
lllll
i.omtltlotlt
MoMt~hotl,f
Adclrffl
'Tu t
,.~
Figura 6.4.2
I
124
ltrt
Design V>rJW
If you are using Access, you can create or amend a database table using
e~her the Dalasheet or the Design view.
One of i he fields in the 'Students' 1able is the Key Field. Look again at
Figure 6.4.2. Can you see wnich field is the Key Field? 11 has a picture of
a key next to ii. It is the ID field, which stores a unique S1uden1ID code.
The data type of the ID field Is 'AutoNumber'. That means the software
w,11 give a new number automatically 10 each record in the da1abase. The
software will also make sure each number ls different.
Create a database
\Nhen using a DBMS such as Access, you crea1e a database by setting
up one or more tables.
Plan
Before you begin you will need to plan carefully.
• A da1abase stores information about entities. Remember an entity can
be a person, a thing. or an event or ac!ion. What different entities do
you need to store informa!ion about? You must create a table for each
type of entity in your database.
• The fields in a table record different attributes (pieces of information).
VVhat attributes do you need 10 store for each en1~? Tr.ese will be 1he
fields of ,he table.
; ACTIVITY
I
In 6.3. you planned a simple
database for use by a ooopera1ive store, showing
cuSlomer details and cuslomer
purchases.
Usi'lg a suttable software
application. create a simple twotable database storing details
of cus1orners in one table and
de1ails of purchases in 1he olner.
• The customer 1able will store
a customer code and a few
de1ails about 1he customer
such as name and phone
number.
• The purchase table will s1ore
the date and 1f1e total value
of each purchase. plus 1he
customer number.
• Make sure every table has a Key Field. This is usually a code number.
• Think about the relationships or links betvveen tables. By using a Key
Field from another table as a Foreign Key you can make a link between
tables.
Design
You can create tables using Da1asheet view. Or you can create the tables
In Design view, by 1yping 1he names and data types.
Amend
All of the attributes of a da:abase can be changed at any time. You can
add new fields, delete fields. change the data type, create or remove
1ables and change the relationships be1ween 1ables.
If you delete a field or make other changes you could lose da1a - so be
careful.
Populate and use a database
\JI/hen your database ls ready you can populate it. That means input data
Into the database. Learn more about data Input in 6.5.
LINK
Once there is data in your database you can:
Input to .i database: 6.5
• search the database to find out information
Searching a datab.ise: 6.6
• print out reports and other useful items.
You will learn more about searching and otJiputs in 6.6 and 6.7.
Find out more about
Outpu:s from a database: 6.7
%
Input to a database
Datasheet entry
LEARNING OUTCOMES
In 6.4, you learned now DBMS
software can be used 10 design
and crea'.e a new database. In
6.5, YOU will learn aboU11he ways
that data are input to a database.
This Is called populating :he
da1abase.
You have seen that it is possible to view a database in the form of a 1able
('Da1asheet view'). Look back at Figure 6.4.1 for an example of this vievv
of a database. You can enter data directly into a datasheet, In 1he same
way that you would type da1a into a spreadsheet.
This option offers no additional help to the person who has to input the
data. If you are entering data into a large data table, with a lot of fields,
the Datasr eet view can be difficutt to use.
Create and use a data entry form
A data entry form gives you an easier way to inpU1 data into a database.
You can design the form with suitable Information, explaining what data
should be entered and selling tt out in an attractive way.
Figure 6 .5.1 shows an example of a data enlry form . The example
shown in this lllustra1ion is provided as a free template witn Microsoft
Access 2016. ft is an example of a form that could be used to enter data
Into a student database.
The person who crea1ed the database designs and creates the data
entry form. The person who has the job ol emering data into the
database, for instance an administrator, can use the data entry form to
type in data and add records to tr,e database.
Validation checks
-
. , _ . OM •
---....
.....
.-.........
r
en ...... - - • • - -
,
-.
,,
-...
,....,
__
---
,_....
Cl 1,r ••
- · ... .
Figure 6.5.1
--·--........
. ....
Exa11ple data ent-y form
-
D
><
One major advan1age of using a
data entry form is that you can build
In validation checks. A validation
check will prevent you from entering
da1a of the wrong type or outside
of the normal range of data. For
example, when entering a date of
birth, tr e software can check that
It is a real date (for instance, the
month must be a number from 1 to
12). See 1. 14 for more about data
validation.
Helpful features
Other helpful features of the data entiy form include:
• clear laycut, with plenty o' space
• helpful explanatory text
• space to enter a student's photo
• drop-down menus for some fields (such as the 'Level' field in this
example) so you can choose from a list of options.
These are the sort of interesting addttional fea1ures tna1 you can provide
in a da1a entry form to make the job of data entry easier.
,. ACTIVITY I
In 6.4, you aeated a da1abase
for a co-operative store.
• Create a data input form to
enter customer reoords into
this dalabase.
• Enter at least ten records using
1he form you have created.
Transaction processing
Typically, a database will have tables of detailed information. entered
once only when a nev>J user is registered. In the student database shown
here. that would be ,he student record. In a library database, tt would be
reoords of books and records of library users.
Many databases also include Information about transactions. A
transacticn is an information exchange. In a libraiy, the main transaction
Is when someone borrows a book. In a studem record system, ,he main
transactlcn might be the attendance register.
In a well-designed database sys1em, the input of transaction information
should be rapid ard easy. Many transaction records might be entered
Into a database every day, so this dala entry should be made as
convenient as possible. Typically, 1ne record of a transaction will require
only the input of one er tv>Jo Key Fields, plus perhaps the date and time.
For example, In 1he relational libraiy database explained in 6.3, a
transaction record consisted of only :he book oode, member oode and
1he date and 11me.
Data input technology
You have learned about ways 1hat data can be inpul automat cal:Y into
a computer system. Look back to 1,6 1o remind yourse~ about tnis.
Examples nclude bar codes and opt cal character recognttion (OCR).
Use of aulomated data entry can be very useful to speed up transaction
processing.
For example, In a library 1here migh1 be a bar code on every library book
and on the borrower's library card. V\!hen a borrower wants to 1ake out a
book, the librarian will:
• scan the bar oode on the library card
• scan the bar oode on the l1braiy bock.
The date and time will be added automatically from the computer's
Internal memory.
The 1•/nole transaction is completed without any typing. In this way. a lot
of transacticns can be processed very rapidly. At.rtomated transactions
are also more reliable. A bar oode reader dces not make typing
mistakes.
LINK
Find out more about
Data input technology: 1.6
Validation: 1.14
C'~
Searching a database
LEARNING OUTCOMES
Once a database has bee"
se: up it can be used to obtain
answers to questions. In 6.6,
you will learn about how DBMS
software enables users to find
the data that tney need l'l a large
database.
Searching
tn a computer studies lesson, students will only have iime 10 create a
small database, with a small number of records and fields. The student
can look through the database table by eye to find the results they want.
But real-life databases vsed in tr,e world of work often have millions of
records. It would be Impossible to find Information by looking through the
tables by eye. For this reason, all DBMS software includes a feature that
searches the database for information.
Features !Ike tnis can be called 'query', ' find', 'extract' or 'filter'. Most
DBMS software will offer more than one way 10 search the database.
Microsoft Access offers a feature called 'Query', whicn offers the user
many different search functions.
Search criteria
When searching for data you typically have to specify a search
criterion. Section 5. 1Oexplains how you can search for information
using crtteria.
Relational operators
The search cmerion will typically specify the name of a field and the
content 10 be searched for in that field. Search criteria typically make
use of relational operators such as =,> and<>. Find out more about
relational operators in 5.2.
For example, a librarian might want to find out if the library has a copy of
Dracula. The query she enters might be something like tnis:
Book Title = 'Dracula'
Book Tttle is the name of the field 10 search. 'Dracula' Is the content to
search for. Because the = {equals) sign is used, the software will search
for a field where the content exactly matches the search criterion.
Logical operato rs
Search crrteria can be combined using logical opere'.ors such as AND
and OR. For example, the librarian might want to know not only whether
1ne library has a copy of Dracula but also whetner it is currently out
on loan.
The search query might be something like this:
Book Title = 'Dracula' AND On Loan = 'N'
This will search for any records of a book with the tiile Dracula and where
1ne book is not currently on loan.
This 1ype of query migh1 seek for data from more than one table. In this
example, the query might search for data from the books table (to find
1he name of 1he book) and 1he transactions table (to find out if 1he book
has been borrowed).
These queries are Just examples; you will be able 10 think of your own
da1a requests a,'1d create suitable queries.
Output required
As well as specifying wha1 records to find in the da1abase. a query will
also specify wha1 resu1is need 10 be output.
For example, In 1he previous q\lery, If the libranan finds there Is a copy o'
Dracula in stock, she might want 10 see the location of the book on the
shelves, so she can go and get it for a library user who has requested rt.
,. ACTIVITY I
In 6.4 and 6.5, you created a
database that could be used by a
co-opera1ive store.
• Create a q~ery form to search
for customer surname. Use 1his
form lo extract one or more
records ftom your database.
• Describe three complex
queries 1ha! a store like this
might find useful 10 help with
1heir bvslness.
A typical database query therefore specifies:
• what fields to search in
• what data to look for
• what data to show.
Types of search
Here are some o' the most common database searches.
• Find a record: The example in this seetion (a librarian searching for
a book Ihle) is an example of a search for a particular record In a
database.
• Fitter a table: In o1her cases, the da1abase user wants lo search 1he
database for a set of records tha1 mee1 a particular criterion. For
example, a school administrator mignt want a 11st of all studen1s due 10
take an exam that day, or a car salesman mlgnt want a list of all cars in
nis shop tha1 cost less tnan $10,000.
• Count records: A simple database search might simply count the
number of records 1hat ma1ch a cri1erion. For example, a school
administrator migh1 want to know how many boys and how many girls
are in the school.
• Calcula1e new da1a: More complica1ed searcnes can be used to
produce new data calcula1ed from the information in the database.
For example, a businessman migh1 want to know the total value of all
orders received that week from customers. Tne softvvare could search
the da1abase 1or all orders placed 1hat week and then use a calculation
to add up 1he total cost.
LINK
Query forms
Find out more about
In modern DBMS software applications, there are features that make it
easier for you to specify a query. Typically 1his is a query form, set out like
a da1abase reoord. You enter 1he data you are looking tor into the form,
and any reoords that match ,his are then displayed on the screen.
Relational operators: 5.2
Search criteria In spreadsheei
examples: 5 .10
%
Database outputs
LEARNING OUTCOMES
In 6.7, you will learn about the
outpuls lhat can be produced
'rom daiabases. Typically, these
are reports 1hat show useful
informahon in an a1trac11ve
format.
Database reports
You can look al a database table on the screen of your compu1er using
Datasheet view. You can also print out the da1ashee1. However, when
working with large databases tt is often more \JSeful to produce a welldesigned database repor1.
A report is a structured printed outpu1 presenting informalicn from the
database in a useful form.
Select fields
When crea1ing a da!abase report, you select whicn fields you wan1 to
Include. Compared 10 simply printing out a data table, this has two
Important advantages:
• A table might have a very large number of fields. When you crea1e a
database report you can choose a small number of fields - just 1he
ones you need. This makes the report neater, simpler and easier
to read.
• Your report could bring togetner fields taken from more than one data
table, such as details of purchases and customer names.
Formatting
Customer Address Book
A
-.---------....
-·-.,n .....
,,t:J )lt- -
B
..,_.,_......,,...,
.,.,ffri......
~,n,• ....,.
E
~,
,m i.-..,...
.,.,.
......
~ntnas...
Figure 6.7.1
--_
.....
-..._
...._
....
Exarnpe of a dataoase repon (MS Access 2007)
\f\lhen you design a database report, you can use all
the typical formatting features. which you have learned
about in other sections. This includes choosing suitable
fonts and colours, layout and headings. Figure 6. 7.1
shows part of a database repon svpplied as a free
example with Microsoft Access 2016. It shows an
outpu1 from a business database, listing oustomer
names and addresses in alphabelical order. h Is
attractively formatted and easy to read. This is an
example of the way a good DBMS can enhance your
reporting.
You can also add images to your reports, such as a
company logo, or a coloured background.
Filtering
1Nhen you create a database report. you can fill er ,he database so that
only some records are shown. In many database systems, the report
feature is combined wltl1 the search feature. Tne softvvare searches
fer records that match 1he search criteria and only tl1ese records are
Included in the report.
Sorting
, ACTIVITY
The example report In Figure 6.7 .1 is sorted in surname order. It is very
common for reports to snow the reoords sorted In order. To specify a
son, typically you select a field and then specify whether the sort should
be in ascending er descending order.
Grouping
Another useful feature is to group tne records in the report imo
categories. Fer example, a report from a student database might show
the students grouped into tr.eir classes or their year group. A report used
by a salesman might group all nls customers by their country or region
so that he can plan his visits.
Summary statistics
In 6.6, you learned about calculaling summary statistics from a
database. Reports can include calculated fields. Examples include:
I
You have created a database
for use by a co-operative store.
Produce a database report
that lists all the customers in
alphabetical order. Format the
report using a suttable layout and
font and any otner features that
seem suitable.
Make sure your database
contains at least ten records of
cuSlomer purchases. Add ex1ra
records if there aren't enough.
Produce a report that calcula:es
the total value of all custcmer
purchases.
• counting the number of records that match a criterion
• adding up subtotals and totals of numerical fields
• calculating means and median values, and other statistics.
You can include these calculated values at the bottom o' a report that
lists records. It is also possible 10 create a very short report that just
contains summary data.
Graphs
Graphs can be used to present summary information from a database.
For example, Figure 6.7.2 shows a graph made using Microsoft Access
2016, produced by Microsoft as an example of what use:ul outputs can
be generated from their software.
Product Sales by Total Revenue
....
....
.51
~
■ Mo.1hl\Wl1-ldia-i
■ lb'lh,,iwlT111dw1,Su,
p ..,........ , ..........._
lf,,;>J
-·-
Figure a. 7.2
-..,oae
. ,_........ ,,~..... c..,.
.k¥erll~
■ Noitlh1'Mdt,ti:1tt-,(h.i
D ~t,~1-CMl:Ma111
■
tfQII...,_. 1,-.-...1, 0-tbt.c
~ .,c.w,. t.11 ..
■ Ntt~1fM5f"l:OMI\~
■ tto,ibM_,T,_..,1 C,afi.-
1
n
-
,,
n
Product>
LINK
■ Notbio,...,U ,.'I C,.6 Mt.ll
■ Noii~T,..,.,C-,nySW(.-
• Nof1twlil-9 ,,-...,, Ot14lld ~
-
Find out more about
Search af1d filter. 6.6
Sorting: 5.9
ExaMole of a da>.aoase gra_oh
%
SECTION 1: Multiple-choice questions
1 You wo1,,ld use a database query to:
create a new table in Design view
b delete a field from the database
a
c
sort a report inlo alphabe,ical order
d locate records !Pal match a criterion
2 A Primary Key must be:
u"lque
b 1ext dale 1ype
a
c
a posttive n.imerical value
d the name of a tabla
3 A record is:
a
a sirgle item of data
b a set of rela;ed fields
c a database 1able
d a summary option
4 Every record in a table nas the same:
a
structure
b content
c Item o' information
d transaction
5 Populating a database means:
7 tf a database report is ~ltered wha, does 1hat
mean?
a All errors are removed before printing
b Tne report Is soned
Only some records are Included In l he report
d Totals are added at tne end o! tne report
c
6 The database software will stop you from
entering data into a field if It:
a has noi been checked by ancther person
b is1alse
c has a typing mistake
d does not match u,e da'.a type
9 Whal Is a Foreign Key?
a A field from ano'.her table, used to link tables
together
b A field ,hat stores da,a in a 'orelgn language
c Tre unique field th;i! identifies every record
in the table
d A search criterion
10 Wnlcn of lhese Is a principle of relational
database design?
a Every table Is llnked to every o:her table
b
Every Item 01 Information is stored O"IYo".ce
b creating a report to show results
c putting information imo the database
c
Trere must be at least 1hree tables In tne
da:abase
d extracting data that ma:ches a query
d
Each item of h formation is stored in more
1han one place, for security
a
designing ;he table Slruclure
6 This symbol might be used in a database query:
<
It is a:
a logical operator
b relational operator
c searcn opera:or
d qt,1ery operator
Further practice questions
and examples can be found at
www.oxfordsecondary.
oom/9780198437215
SECTION 2: Structured questions
1 \/Vhen you define a da1abase field, what
informal ion must you specify?
2 In a database storing Information about all the
voters in a oily, what would you use as a Key
Field? Explain your answer.
3 In a database used In a bank tnere is a one-
to-many relationship between the table of
Bank Customers and the table of Payment
Transaclions. Explain what 1his means.
4 What advantages are tnere to using a data entry
form lnste.id of 1yplng directly Into a database
table?
5 What advantages are tnere 10 creating a
database report instead of just printing cu1 a
database table?
Further practice q1.1estlons
and examples can be found at
www.oxfordsecondary.
com/9780198437215
Problem solving
LEARNING OUTCOMES
The Instructions that computers
'ollow are stored as software
in 1he computer system. A
comp~ter program is a series
of instructions for the col""lputer.
In 7.1, you will learn how
programmers design comp>Jter
programs to solve problems.
The solution 10 a problem is
represented as a design called an
algorr.hm.
In this unit, you wlll learn how computer programmers design software
to solve problems. A formal method for setting out the solution to a
problem is called an algorithm . In this unit you will learn about two
types of algorithm: flowcharts and pseudocode.
The practice exam questions at the end of the unit will help you to test
your knowledge.
Solving problems
Not all real-ltte problems can be solved by computers. In this book
we will concentrate on the klnd of problems that can be solved by a
compU1er. These are generally problems 10 do with numbers and
01her facts.
Problems that computers can help with include:
' ACTIVITY
• matnematlcal calculaticns, such as working out an average or a
percentage
• searching, such as finding the right bock in a library record system
• information storage and transformation, such as increasing the size of
a photo or mixing two music tracks together.
A man runs a holiday club.
Everyone in the club pays a
monthly fee and 1he proceeds are
used to send the whole group
on a noliday once a year. The
man wants to write a comp..,1er
program to tell him how much
money has been saved, and to
print a warning I' anyone is late
with their payment.
To create a solution to a problem of this kind 11".ire are several stages
1hat you must go through.
• Name at least two pieces of
information 1hat he needs to
input each month.
• Defining tne problem: tnis means being dear aboU1 what your siarting
information is and the type of resuh you want (see 'Breaking clown a
problem Into parts' oppostte).
• Name an item of Information he
needs to store from month to
month.
• Describe a calculation that
needs to be carried out.
• As well as the name of anyone
wtio is late with payment, name
one other piece of nformation rt
would be useful 10 output from
the syste'll.
• Propose and evaluate solutions: 1his means proposing suggesticns
aboU1 ways of solving the problem ar>d then evaluating them to get the
most efficient solution.
This unit is abolll designing solutlcns to this type of data-processing
problem.
The steps of problem solving
• Representing the solulion as an algorithm : an algorithm is a way of
writing out the steps of a solution. There is more than cne type of
algorithm. (You will learn more aboUl algorithms in this untt.)
• Testing and validating the algorithm: it is unusual to gel a solution right
first time. Therefore, the algorithm must be tested to find any errors,
which can then be corrected. It Is possible to find and correct many
errors at ,he problem design stage, before tne programmers start their
work. This saves time and trouble.
An efficien1 solution is one that uses the least effort to get ,he mosl
beneftts.
EXAM TIP
Breaking down a problem into parts
In Unit 1, you learned tha1 computer systems Include hardware used
for input, processing, output and storage. These are the normal
components of a computer system.
'Be eLe&1Y t:lbo"'t t he
oliffeye.,,,ee betwee,,,,
These are also 1ne normal components of a computer solution. In
de1ining 1he solution you must define:
fl.owe h&I ,ts &1 ,,,,ol
pseuoloeoole. Sxt:l""-i"'-tYs
Ytport that SO""-t
eti.,,oliolates h&1ve Lost
• Input (vvhat inlormalion will go Into 1he computer)
""-&IYk.s br/ "'Ct reaoli"'-0
• process (how tha1 information will be processed)
• output (wha1 resutts will come out)
• storage (what information needs lo be stored).
the quest,o"" pro-perL1::1.
tf the questi0 ,,,, &lsk.s for
pstuoloeoole, olo.,,,'t clY&1w &1
fl.owe h &1 rt!
Algorithms
An algorithm is a way of setting out the steps of a solution as a
sequence of inslruciions. There is more than one type of algorithm. In
1his book you will learn aboU1 tvvo types of algorithm:
• flowcharts
• pseudocode.
All algorithms set oU1 a sequence of instructions. Specifically, an
algortthm must set out:
KEY TERMS
• what actions lo take (instructions)
way of setti~g out the steps
o• a solution as a sequence of
inslruC:ions.
• in wha1 order (sequence)
• when to stop.
Algorithm An algorithm ls a
A well-designed algorithm will have 1he following features.
• The instructions will be clear and unambiguous, so tha11he person
reading the algortthm knows what actions to take.
• The flow of control - lhe sequence in which to carry out the actions will also be clear.
• Solving tne problem takes a finite number of s1eps.
• There is a single 'termiflator' (or stop) to 1he process.
Testing
Every algorithm mus1 be tested before it is used.
• The algorithm musl be iested 10 find any errors in the design.
• If an error is found, the algorithm must be corrected and the tesl rvn
again.
• VVhen the algorithm passes all tests it can be used as the design of a
computer program.
Turning an algomhm into a computer program is called coding or
programming. You will learn more about programming in Untt 8.
LINK
Find out more about
Software: 1.8
Flowcharts: 7 .3-7.5
Pseudocode: 7.6-7,11
Testing: 7 .13
Programming: Untt 8
%
Variables
Variables
LEARNING OUTCOMES
You have seen tnat a computer
takes l<i'orrnalion, such as
numbers, ar,d processes the
informa1ion. Toe numbers or
other pieces of Information
to be processed are called
values. The values are stored
as variables.
Variables are named areas of computer memory. A variable can be
Imagined as a box, with a label. You can store any value in tnat box.
tf you use the name of a variable in any instruction, the computer goes to
the 'box' (tne area of memory) and uses tile value stored there.
'Nhen you wrtte tne program you will write ins!ructions to:
• give the variable a name
• allow a value to be assigned to the variable.
The name of the variable will be the same each lime you run the program,
but the va'ue stored in the variable can be d1ferent each time.
16
Declaring variables
'Nhen a ccmputer programmer writes a program, he or she will plan
what variables will be needed. The programmer will write inS1ruc1ions to
declare the variables.
Declaring a variable means:
• giving the variable a name
• saying what type of data it will store.
Figure 7.2.1
Puttng the teral value 16
into the var.ao e 'age'
Naming
1Nhen a programmer wrttes a computer program, he or she mus! name
the variables tha1 will be needed. In general, variables snould have short,
simple names.
It is sensible to use meaningful names that remind you of the purpose
of t11e variable. Examples might be 'Age·, 'FlrstName' or 'Cost'. In most
compU1er languages, variable names must begin wtth a letter (not a
number) and must not have spaces in them.
Using meaningful names is a good idea because:
• 11 makes It easier for the programmer 10 design and write the program
KEY TERMS
Variables Varl?bles are named
areas of computer memory.
You oan smre any value In the
variable and 1he value will be
available when the variable name
Is ,sed.
• tt makes It easier i o remember hew the program works at a later dale
• tt makes neasier for other people to understand the work when they
read it.
Always use sensible explanatory names for your variables.
Assigning values to variables
Assigning a value to a variable is like putting a number into 1he box. The
number stored in the box can change. A variable can nave a different
value eacn time the program is run.
There are two ways to assign values to variables.
/ ACTIVITY
I
1 Tr.e value can be input, for example by typing rt in.
2 The value can be calculated, for example by adding or sub:ractlr g.
Constants
Once you nave created a computer program, yov can run it as many
times as you like. Variables are designed to store values that can be
different every time. But some values will not change. They will remain
the same every time you run the program. These values cen be stored
as constants.
\JI/hen you are writing the program you will wrrte instructions to:
• declare the constant
• assign a fixed value to the constant.
Suggest suttable names for
variables that migh! be used 10
store each of these facts:
• the cost of a chocolate bar
• the temperature
• the name of a TV programme
• the age of a school student
• whether a safety switch has
been turned on
• the answer a student gave in a
multiple-choice exam.
Every time you run the program, this fixed value will be assigned 10 the
constant. A non-char ging value that is assigned to a constant is called a
literal.
Arithmetic operators
Instructions that calculate values use symbols called arithmetic
operators.
You should know the following artthmetic operators.
Operator
Meaning
Example of use
+
Add
TotalPay = BasicPay + Bonus
-
Subtract
NetPay = TotalPay - Tax
•
Muhlply
Days = Weeks • 7
I
Divide
Days = Hovrs/24
Integer division
The divide operator divides one number by another. If the number does
not divide exactly then the result includes a decimal.
• Ordinary division The result of the sum 20 divided by 8 Is 2.5.
An al:erna1ive to this is integer division. This is dMsion that gives an
integer result plus a remainder.
• Integer division The result of 20 divided by 8 is 2 remainder 4.
The operators DIV and MOD are used to carry out Integer division.
The operator DIV gives tne result of integer division, but nol the
remainder. So after this command:
Result = 20 DIV 8
The variable 'Result' would hold the value 2.
The operator MOD gives the remainder. So after this command:
Remain = 20 MOD 8
The variable 'Remain' would hold the value 4.
KEY TERMS
Arithmetic opera tors
Arllhmetlc operators are symbols
that allow you 10 perfoITT
mathematlcal processes.
Examples are: - and • and '
a~d/
Flowcharts
LEARNING OUTCOMES
In 7.1, you learned wha1 an
algorithm 1s: a sequence o'
instructions forming the solution
lo a problem, A flowchart ls a
way of setting out or describing
a seque,,oe o' instructions.
In 7.3, you will learn '.he Main
components of a flowchart.
What is a flowchart?
A sequence of aciions can be represented by a diagram called a
flowchart. A flowchart consists of a series of boxes joined by arrows.
• The shape of 1he box tells you the type of action to be carried out.
• The words inside tne box 1ell you the exaci action to be carried out.
• Tne arrows that join the boxes tell you the order in which the actions
mus1 be carried out.
Flowcharts typically s1art at the top of the page, and the arrows point
downwards. Occasionally they are drawn from left 10 right.
Flowchart symbols
Symbol
Name
Usage
(
Terminator
Indicates the start and finish of the
algorithm.
Process
box
The text inside the box explains what
process Is to be carried oUI.
lnpuV
Output
When any value is input to 1he
computer (for example, 1yped in)
or output from the computer (for
example, displayed on the monttor
screen).
A decision with a yes/no or true/false
answer is shown inside the box.
Two arrows come out of the box.
aocording 10 whether the answer is
YES or NO, TRUE or FALSE.
I
)
I
KEY TERMS
Flowchart An algort.hm can be
represented by a diagram called
a flowchart. A ~cwchar. consis1s
o' a series-Of boxes Joined by
wrows.
KEY POINTS
Input/output and Process
boxes elvvays have one wrow
I
I
Decision
box
Directional
arrow
The direction of 1he arrows shows
the order in which the instructions
are carried out (the logic flow).
entering a0 d one arrow leal/ing.
Decision boxes always have
one arrow entering and two
arrows leaving.
A Terminator box <1as one
arrow leaving (Start) or ore arrow
erilerirg finls11).
An example of a flowchart
Figure 7.3.1 shows an example of a simple flowchart lha1 calcula1es a
person's pay by mutt/plying tne rate of pay per hovr by the number of
hours worked.
Here are the actions set out In the flowchart. The red numbers in 1his
lis1 match 1he numbers on ihe flowchart diagram, so you can match the
description to 1he flowchart.
1 The start of the
process is shown by
a ' terminator' box
with the word Start
In It.
ACTIVITY
0
Start
Input Hou·s
2 An input box shows
• If the value 40 was np01 lo the
variable Hours and the value 25
was inout to the variable Pay
Rate, what va'ue was stored n
the variable Pay?
that a value will be
typed in and stored
as the variable
Hours.
© ay = Hou~ • PayRat
3 Another Input box
shows that a value
will be typed In and
stored as the variable
PayRate.
4 A process box shows
that the variable Pay
will be calculated
by muttlplying the
variable Hours by the
variable PayRate.
A computer program based on
the flowchart in Figure 7 .3.1 was
created and run.
©
Output Pay
®
$ too
Figure 7.3,1
Sirr,p~ flowchaR
5 An output box shows that the program will display lhe value of the
variable Pay.
6 The final box Is a terminator wtth tne word Stop in it.
Assigning values
Three variables are used in this flowchart: they are called Hours, PayRate
and Pay.
In 1.12, you learned that values are assigned to variables by being input
or by being calculated.
'Pay s a varlab e
El !Hours •
=
• The values of the variables Hours and PayRate are input.
• The value of the variable Pay is calculated.
PayRate l
'rours • PayRate' Is the
value assgred to
tne vafiaole
The statement that calculates the variable Pay looks like this:
Pay = Hours • PayRate
Figure 7.3.2
This statement uses the ariihmelic operator •, which means 'muttiply'.
l 1-<ow the equals sign Is
used to assign a vaue to
a va·iao!e
The statement has this structure:
• first comes the name of the variable (Pay}
• then comes an equals sign = (this stands for assigning a value}
• after the equals sign comes a statement telling you what value is to be
assigned to the variable (Hours• PayRate}.
All statements assigning a calculated value 10 a variable have this
structure. The equals sign represents assigning a value to a variable.
LINK
Find out more about
Aritnmetic operators: 5.2
%
Logical tests and
decisions
LEARNING OUTCOMES
In 7.3, you saw new a flowchan
can be used to set Ol!i a simple
sequer,ce of Instructions. In
7 .4, you will see how the vse
of decision boxes allows you 10
vary 1he sequence of acllo"s ,n
a flowchart. An action (or series
of actions) that varies In different
conditions Is called a cordltional
sta~ement.
Logical tests
All conditional statements depend on logical t ests. A logical test is one
that has the answer Yes/No (or True/False).
• 'What is your age?' is not a
logical test, because it can
have many different answers.
• 'Are you under 20? ' Is a
logical test, because it has
the answer Yes or No.
In flowcharts, logical 1ests are
written inside decision boxes.
See Figure 7 .4.1.
YES
Figure 7 .4.1
NO
Dec.;, on box
Sequence of control
KEY TERMS
The sequence of actions in a flowchart is shown using arrows. Look again
at Figure 7.4.1 . One arrow comes into tne decision box. li.vo arrows leave
the decision box. The arrows are labelled 'Yes' and 'No'.
Relational operators
• If the answer to the logical test is yes, follow the 'Yes' arrow.
Relational operators are symbols
tnat allow you to compare two
values. Examples are: < and>
and<> and=
• If the answer to the logical 1est is no, follow the 'No' arrow.
Remember, all algor~hms must have a single 'terminator' (er end), so the
two arrows must join up again later.
Conditional statements
So, putting together what you have leamed in this topic:
• Every conditional sta'.ement begins with a logical test, which must
have a Yes/No (or True/False} answer.
• Tne next action 10 take depends on the answer to the logical test. This
is snown by two arrows, labelled 'Yes' and 'No'.
• The arrows must Join up again further along in the flowchart .
• Tnis type of Slrueture is called a conditional statement.
Example
Figure 7.4.2 shows a flowchart that sets out instructions that tell you
whe1her a student has passed or failed an exam.
1 The student's exam mark is input.
2 A decision box asks whether trie exam mark is bigger 1han 49.
3 If 1he answer is 'Yes' then the output is 'Student has passed' .
4 If ttle answer is 'No' then the output Is 'S1udent has not passed'.
5 Tr.e tvvo arrows rejoin al a small circle called a connector - in some
flowcharts no connector symbol is used and tne arrows simply join
together. In any case ail arrows must join together.
6 Tr e flowchart finishes at the 'lerminator' box with the word 'Stop'
in rt.
The new computer game 'War
Machine' can only be boughl
by customers aged over 12.
Create a flowchart ihat sets
out tne following seqi.lence of
lnstruclions:
• Input age.
Start
0
ACTIVITY
• If age is over 12, then output
'You may buy IJ\/ar Macnine',
lnovt
Exam Ma-k
• Otherwise, outpl.ll 'You may not
buy \/<Jar Machine'.
Look at !he example in Figure 7.4.2
for help with this task.
NO
Ou:put 'Student
has passeci'
0
Ou:put 'Student
has no: passed'
sto_P_~J
© (~ __
Figure 7 .4.2
Flo•.vc:nart showscg a oondi: onal sta:ernent
Relational operators
The lcgical test in lhe decision box says :
'ExamMark > 49?'
This means 'Is the exam mark GREATER THAN 49?'
> is a relational operator. The next table shows ,he relational operators
1ha1you should know.
Operator
Meaning
Example
<
Is less than
4 < 100
>
=
Is greater than
Is equal 10
0.5 > 0.25
3 • 4 = 12
<=
>=
Is less '.han or equal to
Is greater than or equal to
Age<= 18
Height >= 1.5 m
<>
Is nol equal lo
(sometimes the symbol .o is used)
25/4 <> 10
KEY POINTS
You have learned two uses o! tne
equals sign. Here rt Is used as a
relational operator to show !hat
tvvo values are equal.
In 7.3 It was used to assign a
value to a variable.
Both l!Ses are correct, and you
will see from lhe con'.ext which
use is meant in eacn case.
Loops
LEARNING OUTCOMES
Flowcharts set out a sequence o1
acl!ons. 1~ 7.5, you will see how
a ~owchart can incl~de a loop
that Is an action (or sequence
of actions) !hat is repeated. Of
course, the actlo"S mus; no:
repeat forever, so there mus: also
be a way of stopping the loop.
Types of loop
A loop shows a set of actions that are repeated. There are two types of
loop, defined by the way that the loop slops.
• Counter-controlled loops repeat a certa n number of times and slop.
• Condition-controlled loops repeat until a certain condition is true.
In 7.5, you will look at how flowcharts are used to set ou1 conditioncontrolled loops.
Control
Exit from a loop is controlled by a decision box (Figure 7.5.1). If tne
answer to the logical test is 'Yes' lhen 1110 arrow continues down the
page. If the answer to the logical test is 'No' then the arrow goes back
up the page, making a locp.
In the example structure shown in Figure 7.5.1 there is only one action
'inside t ne loop', but when you are designing flowchart algortthms there
can be many actions irlSide lhe loop structure.
One important rule in a condition-controlled loop is that it musl be
possible for the loop to stop.
• Extt from the loop is controlled by a decision box (logical test).
Log'cal tesl
Figure 7.5.1
Structu·e of a loop
The test will evaluate a condition or value.
• If the test is ' false' (the answer 'No') then the flow will lcop back and
or e or more actions will be repeated.
• If the test is 'true' (the answer ' Yes') then the loop will slop.
Therefore, whatever 1he test Is, it must be possible to vary that condition
or value to make 1he logical test true so that the loop will s!op.
Example
Figure 7.5.2 Is a flowchart whh a loop structure. That means some
of tne actions In the flowchart may be repeated.
The algoritnm sets out a password test,ing program. The right password
is the word 'Sesame'.
1 The flowchart begins wtth a Start
box.
2 The user Inputs a Password.
0
Start
©
Password
3 Tre decision box tests whe1her the
password is the word 'Sesame'.
4 If 1he answer is Yes (the word
'Sesame' was entered) then the
'Correct password· message Is
output and the algomhm stops.
5 If the answer ,s No (the wrcng
password was typed) 1he arrow
loops back up the page. and the
message 'No, try again' is output.
6 Tne arrow rejoins 1he main
flowchat1 at tl1e top. making a
loop.
lnout
Ou:out · No, t,y
again'
ts'<)
®
©
YES
©
OutP<,JI 'Co·rect
Oa-SS'A'OIO'
(
Figure 7.5.2
Stop
J
Fiowctiart demons,,a:•ng a lcop
The algorithm will loop, The actions inside the loop will repeat until the
right condition Is met (tne rigrit password is typed in).
Notice tha1 the logical test is based on 1he Password variable. So, inside
the loop the user must be able to input a new password. 11 the user was
not able to input a new password, there would be no way to make the
loop stop.
/ ACTIVITY
I
A teacner wants to write a compU1er program to test knowledge of
maths. Create a flowchart 1hat sets oU1 the following sequence of
instructions.
• Output 'V\lhat is 56 + 98?'
• If 1he oorrect answer is input say "Yes. well done' and stop,
• Oiherwlse output 'No, try again' and loop back to ,he slart.
Look at the example flowchart shown in Figure 7.5.2 to help with
this task.
%
LINK
Find out more about
Loops In pseudocode: 7.9-7.11
_-
--,
·---
~ - _ 143.
Pseudocode algorithms
LEARNING OUTCOMES
Psevdooode Is a klnd of
structured Erglisn used
'or describing algorithms.
Pseudocode ls an alternative to
using a flowchart. In 7.6 and trie
pages t/'\at follow, you will learn
how to write algorithms using
pseudocode.
Uses of pseudocode
Pseudocode can be used to define the structure of an algorithm:
• Input values and store t11em In variables.
• Process values, for example :,sing artthmetic operators.
• Output lhe resutts for the user.
This is the basic structure of any algorithm. It is called the IPO model
(that stands tor Input, Processing, Output).
Keywords
When you made a flowchart, you used different shaped boxes to
stand fer different actions such as input, processing and output. In
pseudocode, keywords are used instead. l<eywords can be shown
in upper or lower case. In this book we will use lower case to show
keywords.
Variables
In 7.2, you learned that variables are named areas of computer memory.
Variables are used to store values. Variables should be given sensible
names to remind you of what value !hey will store. In this book we will
give variables an initial capital to distinguish them from keyvvords.
Before a variable is used In a calculation or printed out. it must be given
a value. Tnis is called initialising the variable. A variable can be lnttialised
In two ways:
1 A value is input by tne user.
2 A value is assigned to the variable.
Input a value to a variable
A value may be Input and stored in a variable. For example, the number
of hours worked may be input and stored as the variable 'Hours'. In a
flowchart, this is shown using the following box.
Input Hours
In pseudocode, keywords such as 'read' or 'input' may be used. For
example:
input Hours
r ead Hours
These commands both mean input a value and save tt as a variable
called 'Hours'.
Assign a value to a variable
In a flowchart, a value is assigned 10 a variable using this type of box:
Pay = Hours • PayRate
The equals sign shows that a value is assigned to the variable. The
symbol' Is an arithmetic opera1or. It stands for multiplication.
In pseudocode. the same command is used.
Pa.y = Hours • Pa;vRate
O utput a value
In a flowchart, a value is ou1put using 1he following box. The value of 1he
variable 'Pay' will be printed or displayed for the user.
Output Pay
In pseudocode. the following commands may be used:
write Pa.y
print Pa.y
output Pa.y
dlspla.y Pa.y
All of these commands mean 1/ie same 1hing. The algori1hm will output
1he variable 'Pay'.
ACTIVITY
Sequence of commands
Tnis page shows a pseudocode
algorithm that calculates
pay. Extend the pseudocode
algorithm to:
In a flowchart, the sequence of commands is shown using arrows. The
arrows join 1he boxes together. In pseudocode, there are no arrows. The
sequence is shown by the order in whicn the lines are written. Start at
1he first line and read down the page.
read Hours
read Pa.yRate
Pa.y = Hours • Pa.yRate
print Pa.y
You have learned 1hal algorithms can have other s1ruc1ures as well as a
simple sequence. You have learned about conditional s1a1ements and
loop structures. Yoo can make these structures in pseudocode. More
detail is given on the next few pages.
• calculate tax at 20% of pay
(multiply Pay by 0.2)
• output the amount of tax
• calculate and output take·
home pay, after lax is
deducted.
A well-formed
algorithm
LEARNING OUTCOMES
You have learned how to crea1e
algomhms in pseudocode with
input, precessing and outpv"l. In
7. 7, you will learn how lo make
algorithms that are well-formed
and easy to read.
Improve your algorithms
An algorithm is used as a plan for a computer program. A well-formed
algorithm will be easier to read and easier 10 turn into a program. In this
section, you will learn hew to make sure your algorithms are well formed.
Make your algorithm readable
To make your algorithm readable use sensible variable names. Variable
names should s1art with a letter. Tney may include numbers and the
underline symbol, bU! no otner characters or spaces.
It is good practice to list all the variables at the start of the algorithm. This
is called declaring the variables. In the example on this page we have
used tne variables Hours, PayRate and Pay.
The first line of the pseudocode will declare 1hese variables.
declare Hours, PeyRate, Pay
An algorithm should be clearly laid oU!. Use plenty of white space within
and between lines to make 1hem readable.
Data types
Variables have data types . The data type cf a variable determines woa1
1ype of daia you can store in that variable. This is shown In 1he next
1able.
Data type
What it can store
Can also be called
Boolean
Can only store the values True
or False
Logical
Integer
Can only store l'mole numbers
Can store any number ircluding
decimals and fractions
Can store a single keyboard
character
Can store a series of characters
Real
Character
String
Float
Text
You can only carry out calculations with variables tt they are a numeric
data type (in1eger or real).
The data type of a variable can be set in two ways:
1 Wnen the variable is declared you can state its da1a 1ype.
2 Wnen 1he variable is initialised it will get the data type of tr e value
stored In the variable.
It is good practice to declare variables and set their data type at tne start
of a program. That reduces the chance of incorrect data inputs.
In the example given. Hours could be an integer, while PayRate and Pay
could be real numbers, as mo11ey valves could include a decimal point.
The declaration section would show this.
declare Hours as integer
declare PeyRate, Pey a.s real
Prompts to the user
An input command gets a value from the user and s1ores it In a variable.
For example:
rea.d Hours
But how will the user know what value 10 en1er? H is good practice to
include a message called a 'Promp1' . The promp1 tells the user what
value they have to input. In pseudocode, 1he prompt is generally shown
as a separa1e command before 1he inpU1 command.
print "Enter number of h ours worked"
rea.d Hours
Clear outputs
An oU1put command can be used to display a value. Fer example:
print Pey
But how will the user kl1ow what the output value represents? It is just a
number on the screen. It is good practice to include some explanatory
1ext. In pseudocode, the explanatory text is usually included in 1ne same
print commaricl.
print "Total pay earned is" Pay
Some1imes, the two parts of the prin1 command are joined with a symbol
such as'&':
print "Total pay earned 1s $" & Pay
In this example, a dollar sign has also been included to show that the
value is an amount of currency.
A well-formed pseudocode program
This algorithm has tne same basic s1ruc1ure as the algor~hm you made
on 1he previous page. But tt Is more readable and usable.
declare Hours as integer
declare PayRate, Pay a.s real
print "Enter number of hours \'forked"
rea.d Hours
print "Enter rate of P83"
rea.d PeyRa.te
Pey = Hours • PeyRa.te
print "Total pay earned ts $" & Pay
r ACTIVITY
On the previous page you made
a pseudocode algortthm to
dedue! tax from pay. Turn lhis
into a more readable arid usable
algorithm using 1he me1hods
shown on this page.
Conditional structures
LEARNING OUTCOMES
Algorithms can lncl.1de
conditional structures. A
conditional structure includes a
logical test. In 7.8, you will learn
to create condrtlonal structures ,n
pseudocode.
Actions that depend on logical tests
A conditional structure starts ,vith a logical test. In a flowchart, the logical
test is shown inside a diamond-shaped box. One arrow goes imo the
box and tv,10 arrows come ou1. The arrows point to different actions. One
action is carried out if the teS1 is True. The other action is carried out tt
1he test is False. Look back at 7 .5 for an example.
In pseudocode, you can define a conditional structure using keywords.
The keywords are:
if
then
else
end!f
it.. then
In pseudocode, the conditional structure beghs whh the words:
If... then
The logical test goes between the words ' tt' and 'then'. In this case we
want to test whether a variable called 'ExamMark' stores a value greater
than 49. If the test is true, print out the message 'The pupil has passed
the test'.
If ExamMark> 49 then
print "The pupil has passed the test"
end!f
The command
print "The pupil has passed the test"
is only carried OUI if the test is True.
The word 'endif' marks ihe end of the conditional structure. In this
example, there is only one line between 'then' and ·endff'. But in some
algorithms there may be many lines inside the conditional structure.
it._ then ... else
The structure above includes a command that ls carried out if the test
is True. Vve can also Include a command that is carried out if the test Is
False. We do this using the keyvvord 'else'. Here is an example:
if ExamMark > 49 then
print "The pupil has passed the test"
else
print "Th.e pupil has not passed the test"
end!f
Indentation
The lines inside the condhional structure are indented. 'Indented' means
set in from the rest of tl1e program. The indentation shows which
commands belong Inside the conditional structure.
Using indentation makes the algorfihm more readable.
Nested if
The 'if... else' structure includes one logical test. There are only two
choices - the student has either passed or failed the test.
But sometimes you want to include more than one test with more than
one outcome. For example:
• If the exam mark is greater than 79, then the pupil l1as achieved a
Distinction grade
• If the exam mark is greater than 49, tr.en tne pupil has achieved a
Pass grade
• Otherwise tt:e pupil has not passed .
One way to include several tests is to put one if statement inside anotr er.
This is called a 'nested if'. Double indentation Is used. The nested if
statement Is shown in bold here:
if ExamMar k > 49 then
if Exam.Mark > 79 then
prin t "Distinction"
else
prin t "Pass''
end1f
else
print "The pupU has not passed the test"
end1f
The first test is 'ExamMark> 49'. If this test is true then the second test
Is carried out. The second test Is 'ExamMark> 79'. If this test is also true
then the message 'Distinction' is outpu1.
The use of indentaticn makes the algorithm easier to read. There are two
'else' statements. Indentation helps you to find out which logical test
they belong to. See which test the word 'else' lines up with.
,, ACTIVITY
I
1 Write an algorilhm using 'if .. .
else' that inputs pay and sets
tax a1 30% if pay Is above
99,999 or 20% tt this test is
False.
2 Write an algorilhm using
'nested r• that sets tax at 30%
If pay ls above 99,999 or 20%
If pay is above 50,000. In all
other cases the tax rate is 0.
3 Improve these algortthms by
using the methods shown
In 7. 710 improve usability
and readability. Print out the
resulting tax deduction and net
pay.
Counter-controlled
loops
LEARNING OUTCOMES
An algorilhm can include a loop.
The commands inside a loop are
repeated. In 7.9. you will learn to
create a psevdooode algorltnl'l
:hat lncl.,des a loop.
Loops
A pseudooode algorithm can include a loop. The ccmmands inside the
loop will be repealed. Every loop must include an exit condition. The exit
condttion stops the loop from repealing. OtherNise, the loop would never
stop running.
By using a loop you can make a quite short algorithm that does a lot of
work.
Iteration
A loop contains one or more aotions. These actions may be done once,
or many times, depending on how many times the loop is repeated.
Each repetition of the actions inside the loop Is called an 'iteration' of the
actions.
Types of loop
There are two main types of loop. They have different extt conditions:
• Counter-controlled loops repeat a set number o' times.
• Condttion-oontrolled loops are stopped by a logical test.
You will learn abou1 counter-controlled loops on this page. You will learn
about condition-controlled loops in 7.1 O and 7.11 .
Counter-controlled loops
Counter-controlled loops are controlled by a variable called the 'counter' .
Programmers generally call this variable I (not cap~alised). The counter
will count from one number 10 ano'.her. Every lime !he loop iterates, the
coumer goes up by one. Wnen it reaches the higher number, tt stops
tne loop.
Here is an example. Tre counter will count 1rom 1 to 5. This algorithm
will print 'Hello' five times.
for i = lto5
print "hello"
next !
Notice tha11he actions that belong 'inside' the loop are lndemed. That
makes the program more readable.
Here is ano:her example. This algorithm will print the nine times table.
for I " 1 to 12
Number = 9•1
print Number
next i
Sometimes the counter stares at 0. This algortthm will add up the total of
ten numbers
Total " 0
forl = Oto9
input Number
Total= Total+ Number
next I
print Tota.I
Nested structures
You can put a condltional structure inside a loop. The condttional
structure will be carried out with every iteration of the loop.
The fellowing algorlthm will find the largest of a series of 100 numbers.
Before the loop begins the largest value is 0. \/Vith each iteration a
number is input. Each number Is compared to the largest. If it Is bigger
than the largest so far, it becomes the largest value.
Lar gest= 0
for i = 1 to 100
input Number
if Number > La.rgest
La.rgest = Number
enclif
next i
print La.rgest
ACTIVITY
When to use a For loop
A For loop is used when you know In advance now many iterations you
need. For example, tt you want to print a result for each month of the
year. you know you need 12 iterations. If a teacher wants :o evaluate
tesl results, she might need as many iterations as there are pupils in her
class.
You created an algortthm to work
out the pay of one employee.
Wme an algorithm that will
repeat this calculation for ten
employees.
Condition-controlled
loops
LEARNING OUTCOMES
In 7.9, you learned about
counter-co.,1rolled loops fnat
repeat a certain number of times.
In 7.10 and 7.11 , you will learn
about the otrer type of loop - a
conditlon-con1rolled loop.
Condition-controlled loops
As you saw in 7.9, the tvvo types of loop are distinguished by the method
used to stop the tteralion: in other words, how you extt from the loop. A
condttion-oontrolled loop is stopped by a yes/no or trve/false test.
When you use a condt ion-corrtrolled loop you do not decide in advance
how many iterations will take place. Instead you must decide what
condition will cause the loop to stop.
When to use a condition-controlled loop
Use a condition-controlled loop when you want an action to be repeated
until a particular goal is achieved, or until the process has lo stop.
For example, a computer might be used to control a robot that hammers
a piece of metal. The robot will keep hammering until the metal is flat.
This is an example of a oondition-cc<11rolled loop. You do not know how
many times toe robot will need to hammer the metal. Instead, you know
wna11he goal is and the computer tterates the process until the goal Is
achieved.
Or, in a business context, a ba0k might pay out money lo a customer
until his account is empty. You do not say how many times he can take
money out, but you say when the process has to stop.
Rules of condition-controlled loops
The condtticn that causes the loop to stop must be a logical (yes/no)
test. The test will evaluate a value, typically using a relational opera1or
such as = or <>.
The value that is tested must be something that can change. If the value
always stayed the same, then the loop would never stop.
So, remember wr.en making a condttion-oontrolled loop:
• there must be a logical test 10 stop the loop
• the value that is tested must be a variable
• the algortthm must include actions that change the value of the
variable, so that the loop can stop.
While loop
There is more than one way of making a condition-oomrolled loop In
pseudooode. In this section, you will learn about a type of loop called
'While loop'. In this type of loop, the actions will repeat WHILE a
condttion is TRUE.
The structure of a \/Vhile loop in pseudocode is as follows:
'll'Tbile test
co=ands
end'll'Thile
ACTIVITY
• If the test is true, the commands will be carried 0 1.rt.
A teacher wants to write a
computer program to test
knowledge of maths. Create
a pseudooode algori!Pm that sets
o..rt t11e following sequence of
insl1'uctions.
• If the test is false, the loop will stop.
• Output 'What is 56 ... 98?'
Notice that if ,he test is false at the start of tne process there will be no
Iterations at all. That means that in certain conditions, the actions inside
the loop will not be carried out even or1ee.
• Input an a'lswer.
• If the correct answer is input
say 'Yes, well done' and Slop.
• Otner,,vise output 'No, 1ry
again' and repeat the actions.
You oan create this algorithm
by adapting the pseudooode
example on this page. You
will have to amend it In
several ways.
Instead of the word 'test', include a logical test. Instead of the word
'commands' . Include the commands you want to repeat inside the loop.
Example of a While loop
Figure 7.5.2 showed a flowchart with a cond~ion-controlled loop. Look
back at this example 10 remind yoursett of the structure. The action that
was repeated was asking the user to input a password. The condition
that stopped the loop was If 1he user typed the right password (the word
'Sesame').
If the test is true
Remember, if the test is true then the loop will repeat. You want the loop
to repeat if Ir e user types Ir e wrong password. So the test is:
Pass\vord <> 'Sesame'
Notice the test condition uses the relational operator <>, which means
'Is not equal to' . The loop will repeat while the password is not equal to
'Sesame'.
You must be able to change the variable
Remember that you must give the user the chance to extt from the loop.
That means in this case you must give them the chance to enter a fresh
password. So remember to include 'lnpl.ll Password' within the loop.
Here is the full example:
input Password
'll'Thile Password <> 'Sesame'
output 'Wrong passv1Tord, try again '
input Password
end'll'Thile
output 'Correct Password'
LINK
%
Find out more about
Relational operators: 7.4
Condttiori-controlled loops using
ffowoharts: 7.5
Different kinds of
condition-controlled loop
LEARNING OUTCOMES
You are learning ,o vse cofldltloncontrolled loops. This type of
loop is oon:rolled by a logical
tesl. In 7 .1 1, you will learn about
'Repeat Until' loops. This type of
loop stops when the test is ;r... e.
Condition-controlled loops
You have learned that condition-oontrolled loops are controlled by a
logical test. There are two types of condition-oomrolled loop.
1 While loop It loops while the test is true. \Nhen tne test is false, tt
stops.
2 Repeat Until loop It loops until the test is true. When the test is true it
stops.
In 7.1 0, you learned about 'while' loops. In 7.11, you will learn about
'repeat until ' loops.
Test is at the bottom of the loop
Different programming languages have different ways of implementing
loops. The position of the test can be different in different languages.
The test in a 'while· loop is placed at the top of the loop. That is the style
of loop that you learned on the previous page.
The test for an 'repeat until' loop goes at the bottom of the loop. Here is
an example:
repeat
Input Passv1ord
until Password = 'Sesame'
How to stop the loop
A repeat vntil loop and a while loop use opposite tests. The while loop
repeats when the test is true. So in the password example, tr e test will
check whether the password is wrong. If the password ls wrong, t11e
loop continues.
while Passv1ord <> 'Sesame'
A repeat vntil loop uses the opposite test. It tests if the password Is right.
If the password is right the loop stops.
until Passv1ord = 'Sesame'
Effect of test position
In a while loop, the test is at the lop of the loop. This has some effect on
how you wri!e the algorithm:
• Tne test uses a variable. The variable must be given a value before the
loop starts.
• If the test is false at the start of the loop, the commands inside the
loop will not be carried out even orlCe.
I
154
In a repeat umil loop the teSl is at the bottom of the loop. This changes
the way the algorithm works.
• Because the test comes at the end of the loop, you can set the value
of the variable inside the loop structure. There is no need to set it
before the loop starts.
• The test comes at the end of !Pe loop. That means that the oommands
Inside the loop will be carried out at leaSl once, even if the test Is true.
Example: add up a list of numbers
A student had to write an algorilhm to add up a list of numbers to give a
tolal. The loop will stop if the user enters the number O.
Here is the algorithm using a wnile loop.
Total = 0
Input Number
~vblle Number <> 0
Total= Total+ Number
input Number
end \'lhlle
print Tota.!
When a while loop is used. ,he first number must be input before tne
loop begins. That is so the logical teSl can be earned out at the top of
the loop.
Here is the same algortthm made using an until loop.
Total = 0
repea.t
input Number
Total= Total+ Number
until Number = 0
print Tota.l
There is no need to enter the first number before the loop begins.
However, because tl1e test comes at the bottom of the loop. ll1e
commands inside the loop must be carried out at least once.
/ ACTIVITY
1 Write an algorithm to add up a
list of numbers and slop when
the total is greater than 100.
Use a repeat until loop.
2 Wrtte an algorithm to add up a
list of numbers and stop when
1he total is greater than 100.
Use a while loop.
3 Wrile an algorithm to add up
a list of r umbers. After each
number a question appears
'Do you vvant to e<1ter another
number? (YIN)'. If !he user
types N, the loop stops. Use a
repeat until locp.
Logical operators
LEARNING OUTCOMES
You have learned about
conditional structures
(If... Tren) and conditioncontrolled loops (Wnile ..•
Do). Both of these algomhm
structures make u$e of logical
iesls, which have a yes/no (or
tl'\.le/false) answer. In 7, 12. you
will learn row to bring together
a group of tv,,o or mere logical
tests using logical operators.
Operators
There are !hree types of operator that you need to know about.
• Arithmetic operators such as+ and ' (see 7 .2) are used 10 perform
calculallons. tor example, when assigning values to variables.
• Relational operators such as < and <= (see 7.4) are used to compare
values to create logical tests.
• Logical operators described in this topic are used to combine logical
statements to create more complex logical tests.
Logical operators
The tnree logical operators tnat you need 10 kf,ow about are AND. OR
and NOT. AND and OR are used to join together two logical tests. NOT
is put in front of a logical test to reverse its meaning.
The next table shows the three logical operators.
KEY TERMS
Logical operators Logical
operators allow you tc combine
yes/no statements to give a
statement that Is erther :n.,e or
false. Examples are: AND and
OR and NOT.
Operat or
Example
Meaning
AND
OR
(x) AND (y) Bo'.h the statements x and y are tn;e
(x) OR (y)
At least one ol the statements x and y is trve
NOT
NOT(x)
Statement x is nol true
Where the letters x and y are shown, you would p ut a logical ,est.
Example: AND
In 7.8, there was an example of a pseudocode algorithm to test whether
students had passed an exam. II included this line:
if ExamMark > 49 then
This logical test asks whether the exam mark variable has a val~e greater
than 49 .
In the next example the pupil has to get a mark above 49 in an exam,
AND a mark above 29 In an essay, in order 10 pass the course.
input ExamMark
input EsseyMark
if (ExamMark > 49) AND ( EsseyMark > 29)
then
output 'PupU has passed'
else
output 'Pupil has not passed'
end!f
The statement
(Exa.mMa.rk > 49) AND (ESSllJ'Mark > 29)
combines 1wo logical 1ests using 1he logical opera1or AND. If both 1es1s
are true then 1he whole expression is true.
Example: NOT
In 7.11 , you saw an example of a conditional loop tha1 repeated so long
as the t.1Ser did no1 enter 1he password 'Sesame'.
~vblle Password <> 'Sesame'
output 'Wrong passv1Tord'
input Pa.sS\VOrd
end111bile
The rela1ional operalor <> Is used to mean 'is not equal to'. Instead of
using this operator the same loop could be written using the equals sign
and the logical operator NOT.
whlle NOT (Password = 'Sesame')
output 'Wrong password'
Input Pa.ssword
endwhile
There is sometimes more than one way of achieving ihe right result In a
program or algorithm.
Truth tables
All the possible trulh values for AND, OR and NOT are set out iri the
following table.
X
y
xANDy
x ORy
NOT(x)
True
True
True
True
False
True
False
False
True
False
False
True
True
False
True
False
False
False
False
True
The first I ne of this tab.e tells you that ~ x 1s TRUE and y is TRUE, then:
• the expression (x AND y) is TRUE
• the expression (x OR y) is TRUE
• the expression NOT(x) is FALSE.
Whal do the other lines of the table tell you?
,. ACTIVITY
I
V\/rtte out in words the meaning of each line of the lruih 1able.
LINK
Find out more about
Arithmetic operators: 7.2
Relational operators: 7.ll
%
Testing
LEARNING OUTCOMES
In tnis untt, you nave learned
aboU1 how to read a0 d design
algorithms 1.,slng two methods:
flowcharts and pseudocode.
In Unit 8, you will learn how
algort.hms are ,urned Into
computer programs.
Before you turn an algorithm Into
a pr09rarn, It must be thoroughly
les1ed to make sure n works
properly. If any errors are found,
lhey must be cOrremed and
lested again, In 7.13, you will
lear0 abolt. the me1hods used to
test algori1hms.
Dry run
The way to test an algorithm is to perform a dry run. This means you
read through the algorithm, step by s,ep, following the instructions in
order. noting the values stored in each variable at each stage of the
process.
You must decide what values to use as input - this is the test data.
The values of the variables are noted down using a trace table.
Test data
You should perform a range of tests, using different input data, to
make sure that the algorithm works as you want tt to in a range of
circums!ances.
• Your tests should include examples of 'normal' data. This is tne type
of data you would input during normal use of the planned compi.rter
program. The algor~hm should process this type of normal data to
give you the answers you expect.
• Your tests shOuld include examples cf 'extreme' data. These are data
at the extremes or boundaries of what is acceptable in your design. For
example, if 'age' is to be input and the maximum acceptable age is 18,
then ,he important values to test are 18 and 19.
• Ycvr 1ests should include examples of 'impossible' or 'null' data. For
example, what happens if you enter a negative number. or letters
instead of numbers.?
Make sure that in your tests you include a wide range of input data.
1Nhen testing an algorithm, you need to run many tests. Even if your
algortthm passes one test, that does nol mean It will work correctly every
timel
EXAM TIP
Wne"" tJOK t!Ye CYetrti"'-g
a"' atgo.,.i.tn""-, "<-ti ~e Suye
a""l::) Loop stYuctuYe ltias a"'
ex,t co""cli.ti.o"' a.,._a tniit
tJ~t.<Y tYtrce table .,.eflects
titJLS.
Trace table
A trace table has a column for each variable used In t11e algorithm. As
you work your way through the dry run you use the trace table to no'.e
dovvn tne value of each variable at each slage of the process.
In a very simple trace table (see Example 1) you might have a row for
each line of the algorithm.
If you are testing a sligntly longer algorit11m, for example, one that
Includes a loop (see Example 2), then typically t11ere is one row in the
1able for each iteration of the loop.
Example 1: Simple algorithm
You have seen this algorithm before {for example, In 7.6).
Input Hours
input Rate
Fey = Hours • Rate
output Fey
A pupil decided to test this algorithm using as test data 12 for Hours and
5 .25 for Rate.
The following trace table shows the results.
Line
H ours
Rate
Pay
input Hours
12
-
input Rate
12
5.25
-
Pay = Hours • Rate
12
output Pay
12
5.25
5.25
63
63
Example 2: Algorithm with loop
The following algortthm de'.ermines the biggest number in a sequence of
ten Input numbers.
Biggest = O
forl =ltol O
input Number
If Number > Biggest
Biggest = Number
I
1
7
10
6
10
10
7
8
11
10
11
8
4
9
2
11
11
n ext i
print Largest
3
4
A student decided to carry out a dry run of this algortthm.
5
Her test data had to be 1en numbers. She chose the numbers
6
The trace table is shown in Figure 7 .13.1.
/ ACTIV ITY
6
7
6
7
1
2
As tne algomhm has a loop in tt, a trace table was created that has one
table row for each iteration of !he loop.
Bigge st
0
endif
6 . 7, 1, 10, 6, 8, 11, 4. 2, 1
Number
10
1
Figu"' 7.13.1 I Trace tabe
11
I
Create a trace table. and perform a dry run on tt.e following
algortthm. using suttable test data.
Total : O
for 1 : 1 to 10
Input Number
Total = Total + Number
nextJ
print Total
LINK
('~
Find out more about
Turning algorithms into programs:
Unit 8
SECTION 1: Multlple-cholce questions
1 Vvh,ch of the following seq~enoes represents the
steps of problem solving In the correct order?
a Develop an algorithm; test tl>e solution; define
1he problem; propose and evaluate soll.llions;
determlne the most efficient sol<.rtion.
b Propose and evaluate solutions; determi~e
1he most ef'icient solution; 1es1!he solution;
develop an algorithm: de'lne the problem.
c Define me problem: propose and eval.;ate
solutions; deiermine 1he most efficient solution;
develop ari algcri!Pm; tes1 the solution.
d Define tt,e problem; determine the most
eff,cient solution: develop an algori!hm: test
1he solution; propose and evaluate solutions.
2 A problem can be broken down into four
signttlcant parts:
a input, throoghput, process, outp;.rt
b Input, process, s1orage, output
c Input, display. otr.put, printing
d Input, process, storage, archiving
3 What is the difference between variables and
constants?
a Variables are areas o' storage wnose values
can cha",ge dvring processing: values In
cons:ants never change.
b Variables are areas o' storage wnose values
never change during processing; values ln
constants constantly chll"ge.
c Variables are areas o' storage wnose values
vary from one to 100; values In oonstants
never change.
d Variables are areas o' storage wnose values
can change d-.1rlng processing; values In
constants constantly cha,,ge.
6 Algorithms can be represented as:
pseudooode or flowcharts
for loop or while loop
c trace table or truth table
d variables or constarr.s
a
b
7 Which of 1he followi'>g pseudocode sta:ements
would display only those scores that are 40 and
above?
a tt Soore > 40 then print Score
b tt Soore <; 40 '.hen print Score
c ij Score <> 40 then print Score
d if Score >= 40 then print Score
8 Here is an example of an algor'rthm.
Input A
Input
:e
C=A+B
C = C + 12
print C
What would be printed If :he numbers 7 and 9
were inp..rt?
a 16
b 28
C
d
9 Here is an example of an algorithm.
input A
Input B
C=A+B
1f A>
then
:e
C=C+l
else
C = 0 -1
end.if
4 Which of the following Is not a suitable data type
for a variable?
a Integer
b Character
c Prccedure
d Real
5 \1\/hich of the following Is not a good feature of an
algoritnm?
a Shows a number o' steps
b Shows the sequerce of steps
c Can be lnterpre1ed in many different ways
d Has an end point
II
1eo
12
9
print C
What would be primed if l he r>Urnbers 6 and 8
were input?
a
6
b
8
C
13
d
16
/
~
Further praetioe questions
~~
and examples can be found at
www.oxfordsecondary.
com/g780 198437215
SECTION 2: Structured questions
1 a
b
2 a
A worker is paid at the rate of $90.00 per
day and might wor'k up to six days per
week. Write an algortthm 10 accept 1he rate
o' pay and 1he number ol days worked. The
algorithm should then calculate and print the
weekly salary paid to a worker.
Extend the algortthm in part a 10 ir,clude a
bon..is of $150.00 wr,ich s!>ould be added to
the salary If the worker's basic salary is more
wan $450.00. Print the new salary.
There are 15 students In a class. Write an
algorithm to accept tne mark scored by each
Sludent. The algomhm snotJld determine and
print the highest score.
b Write an algortthm to read a number of
Integers. The algortthm should determi'le
ard print the sum of all numbers read. The
algoritnm should terminate wnen 999 Is
8/ltered.
3 Using the following algorithm, complete a copy
of the trace table given that X = '-.
X
M
y
4
1
3
4
4
4
4 Copy and complete the lraoe table below, using
the following algorithm.
B=4
C=6
Total= 5
While B <= 78 Do
B=B+C
C=C + B
Total = Total + C
EndWh!le
Print Total
B
C
Total
4
6
5
Start
ReadX
ForM= 1 toXDo
Y=X-M
Z=5*Y-M
Enc!For
Stop
z
Further practice questions
and examples can be found at
www.oxfcrdsecondary.
com/9780198437215
Programming languages
LEARNING OUTCOMES
Urit 8 'oc.ses on !earr ing to
create computer programs. In
8.1 , you w,11 learn abov1 l he
dif'erent computer programl"'llng
languages and wrry l hey are
used.
Machine code
A computer is a piece of electronic machinery. There is nothing inside
the computer except electrical signals travelling througn circuits. These
electrical signals make numbers. So all informailon inside a computer
must be stored in the form of electronic numbers.
Even the instructions that control the computer are stored as electronic
numbers. Every action (like 'add two numbers' or 'store the result') has
its own code number. Tne computer reads the code numbers one after
the other and carries out the instructions. This is called 'executing' the
inslrvC!ions.
This number code is called machine code. It is a code that the machine
understands. Using machine code we can tell the computer what to do.
Software files are made of machine code. When ycu load software into
the computer ready to use, all tr,e eleclronic numbers are copied into
an area of tne computer's memory. Wnen you run the file the computer
'executes' me instructions. So a file made of machine code inst11Jctions is
called an executable file.
Assembly language
Machine code is good for computers. But it diffioult for people to read
and write instructions in machine code.
The early computer programmers invented an atternative to machine
code. It is called assembly language. Assembly language uses code
words Instead of code numbers. Fer example, the code to 'add' is the
word 'ADD'. The code to 'store' a number in memory is 'STA' and so on.
It is easier for programmers to read and write programs in assembly
language than machine code. Thai is beca~se they are made of
words instead of numbers. But tt is still quite challenging to get the
instructions right.
A piece of software called an assembler will read the letter codes and
turn each inslrvclions into machine code numbers.
1 !Uaple of !Ill( :;c auab:y hn;11.1s-•
r.m.htr :.r; rt~hlAr Ali;
J 1ubt.ra~u •• If !.t. ii ii:. C.1 r•r.s• 101.. u;,
J Ac~iu •
, c,U..rrlH l 11vu a nn~~d.
High-level languages
111!0
Machine code and assembly language are called low-level languages.
They are su~able for computers but hard for people 10 use. Programmers
scmetlmes write small pieces of code using low- level languages. Code
written in this way can be fast arn:l efficien1. Buth is very difficult to use a
low-level language to write complex programs.
~•n
1 ~du:• ~in1
I ~ • n .U to 107
I !.f 1111, j,;a; to :>:Oil
I COO,lrt U. to 112
IIRUC
CD J.>:, 101
:t
:>l)lt
:o AX, 1U
;; ~:lllE
,ua >.x, u
llUr;'l t
P.U
Sll3'i
IIIDi'
Figure 8.1.2
1 H srntu,
lU1J1 to Dair::
1 •~tnet 4i .res. U
1 Htl~rn to Dain pros-ru;
J ~dur• c!• htn
I Th<S 1s what asserr.b'Y
ang,;age OOKS <8
So new programming languages were invented. Trese are called highlevel languages. High-level languages are designed wtth the human user
In mind. tt is easier to write programs in high-level languages. You will
learn a high-level language (\/BA) In this unit.
Examples of hign-level languages include Pascal, Python. C and Java.
fl (
,
I Ii w,t
1ett
foo tNin.cpP No Solcctloft
KEY POINTS
<iost,.eam>
'a #include
using na11espace std :
Machine code is a number
~
code. There is a code " Umber
for every action the comput11r
can do. The computer reads
the n.imbers a" d 'executes' the
1nstruclions 1n order.
', Int ■ainO
1
,
{
,. }
cout << "Hel l o, worldl \ n• ;
return O;
II
Figura 8.1.3
I A short program wntten In C++
Each programming language has advantages and disadVanlages. Most
programmers have one or lwo languages they prefer to use.
~ I-WlcfflOl'ld.,---• 11'
...,.:kage ¢':&• ..._1._.t..1bwu.H:
>
.. .
.-,.tie d-A.ii• 1'-llotlodd C
tl'llblJ.c • i.Uc wJdl •UlluU19{J upl I
tfatta.oa.t,p.n:iu~r.._uo -.orHrl J:
Figure 8.1.4
-
A short prog-am wntten In Java
Figures 8.1 .3 and 8.1 .4 show examples of programs in Java and c~+.
These 1wo programs do the same lhing. They display the message
'Hello V\lorld' on the screen. But the code used is different.
Programs written in a high-level language must be turned Into machine
code so lhe computer can understand them. Learn more about
lranslating inlo machine code in 8.3.
/ ACTIVITY
I
Find lhe name of anolher highlevel language, one not shown on
this page. Find an example of a
program wrttten in the language.
Look at tne code and see if you
can understand what tt does.
LINK
Find out more about
Software: 1.8
('~
Using VBA with Excel
LEARNING OUTCOMES
In 8.1 , you learnect :hat
programs are written using nlgl'ilevel languages. You will learn a
language cailed VBA. In 8.2, you
will see how to prepare Excel so
you can wnte programs attached
to an Excel spreactsheet.
What is VBA?
Visual Basic is a high-level programming language invented by Microsoft.
VBA is a version of Visual Basic, which is provided as part of Microsoft
Office.
VBA stenos for 'Visual Basic Applications'. That means it is a version of
Visual Basic tha1 works witn other Microsoft applications. In this book
you will learn 1o write programs in VBA.
Customise the ribbon
VBA is linked to all 11'e Office applications. You are going to use the
version attached to Excel. Most people who use Excel do not write VBA
programs. Only expert developers use VBA. So before you begin. you
must make some changes to Excel.
Open Excel. Across lhe top of 1he screen you will see a kind of 'tool bar'
with icons that stand for different actions. This is called 1he 'Ribbon'.
• Right click on the ribbon. Click in 1/ie space betvveen the icons.
• A drop-down menu appears (see Figure 8.2. t). Cnoose 'customise the
ribbon' from the menu.
...
---- •
•
I -
t•
!
Figure 8.2.2
•
•
..., .X,cut
C) ll@i Copy •
Paste
•
t
•
"- Fo,ma:t Painter
aiu vrM
l!l E2) Fotmulas
l!J E2) Dau
!!l E2) R.v,...
l!I E2)V,ow
l!I
Add+l('IS
l!J E2) Fo,dt POf
,l!J 0 ACROBAT
Figure 8.2.3
8
J
- 11
U
r.
Add to Quick Atcess Toclb.ar
A
tunomilt Qurck Acce:s l oolb,r,.,
Show Q<,,clc Access Toolbar Btlow !ht Ribbon
Cvsto.m1n .the Bibbon....
Collapse the R.bbon
,____J
!!l 0 P•ge layout
C1hbn
I
F
Figure 8.2.1
A big window appears with a lot of options (see Figure 8.2.2).
• Look on the right-hanct side of tl1e winctow and find the word
'Developer' (see Figure 8.2.3). Click to tick 1he empty box next 10 this
word .
• Click on tne OK button in tr e bottom left corner of 1he window.
The Developer tab
i;
...,.
Look at the tabs at the top of Excel. Yov will see a
new tab called 'Developer'. From now on you will
a~"lays see this tab when you start Excel.
,.......;..~
Click on lhe Developer 1ab and you will see some
new icons.
Figure 8.2.4
,_
-·
·•--~-·
·-·
- - r ............
.......
.... .............
.__......
...
,,.~
~
=
......
it t(
~
...
lai
a--M9t,.......
Dev~oper tab
The first icon says 'Visual Basic'. Click on this icon.
Start Visual Basic
When you click on this icon you will see the VBA wim:low on your screen.
The 1•/nite window on the righi is where you will write VBA code.
Save for next time
Save tne file for next time. You musl save it as a 'Macro-Enabled
1Norkbook'. That means an Excel file that can run VBA programs.
Figure 8.2.5
I
VBA w,noow
File name: My project workbook
Save as type: Excel Workbook
V
Excel Workbook
Excel Macro-Enabled Workbook
Excel Binary Workbook
Excel 97-2003 Workbook
Figure 8.2.6
Sava as Macro-Enabled \i\lor'<ioook
You can use any name 'or the file. For example, 'My VBA workbook'.
Note
If the coding window doesn't appear. make sure the Excel workbook is
selected and click on the 'view code' Icon.
~ Microsoft Visulll Basic for Ap
f ile
fdit
Yiew
!nsert
F,2rmat
/ ACTIVITY
Set 1,p your copy o' Excel so 1hat
you can use VBA as shown on
this page.
· liJ ~ ~ lii1
Project• VBAProject
LINK
Find out more about
SpreadSl'eets: Unit 5
[3, Vi ew Code jed: (Bookl)
,::;-c:r.,...,rosoft Excel Objects
~-·f lhisWori<book
Sheetl (Sheetl)
',ti
Figure 8.2.7
VifYl•' code
%
Program development
LEARNING OUTCOMES
You nave se1 up Excel ready to
write a VBA program. In 8.3,
you will wrtte a shon VBA
program and learn about
:he process of program
de11elopmen:.
Program development
The process of program development has the following stages:
• Create :he source code.
• Translate tt inlo machine code.
• Run (er 'execute') the machine code.
• C"eck !he program and remove any errors.
• Ptogram maintenance.
On this page we will follow lhe stages using a simple example program.
Create sou rce code
Source code means the code written in your chosen high-level
language.
In VBA, source code is held in a file called a Module. The first Siep is 10
create an empty module:
• Start Excel and click on the Developer tab.
• Click on the Visual Basic icon to open the VBA window.
• Insert a module. The default name is 'Module 1' and you can use this
name.
t, ...............-..,,
Figure 8.3.1
Inside the module you will write lots of snort programs. In VBA these are
called sub-procedures.
Your first Sub-procedure is called HelloWorld. Click in the code window
and type the following text.
Sub HelloWorld()
VBA will mark the end of the sub-procedvre by entering 'End Sub' two
lines down the screen.
Now you "'~II tell the computer to show a Message Box that says 'Hello
World' . In between 'Sub' and 'End Sub' wrtte this line of code. You can
add Indentation to make your code more readable.
M sgBox("Hello World")
The screen now looks like Figure 8.3.2.
This is your firs1 VBA program. This Is an example of source code.
Translate into machine code
Remember, the compl.rter can't understand source code. It can only
understand machine code. Source code needs to be turned into
machine code before the compi.rter can execute tt.
There are tvvo ways to translate source code into machine code:
interpret er compile the code.
..,,•-
---
Figure 8.3.2
I
• Interpret the source code: Each command In tne program is
converted. The maw ine code ir1Struction is sen1 straight away 10 the
computer, which carries out the command.
• Compile 1he source code: All ihe commands In the program are
converted. The maw ine code ir1Structions are not carried out. They
are stored as an ·executable file' of machine code.
VBA offers beth choices. We will interpret the source code because this
Is quicker and you get an Immediate result.
.. ..................... .e- .......
■ a• _,
Figure 8.3.3
"t
• •
• IC'-:1 1-t
I
Execute or run the program
If you compile tne source oode, you make an executable file. Tnen you
must execute tne file. Bui we ,,AUInterpret the source code. That means
translation and execution happen in one go.
• Make sure 1ne cursor is In 1he sub-procedure 'HelloWorld'.
• Click on t'l1e green arrow in the Visual Basic toolbar (see Figure 8.3.3). It is
Just below the word 'Debug'.
M<aosaftE.cel
The program will run. You should see Figure 8.3.4 on the screen.
Hrllo World
If you had compiled the program, the machine code would be stored
In a new file. You would have to find and run that file to execute tl1e
commands in your program.
Debug and maintain
Figure 8.3.4
I
The final S!ages of program developmetit are to debug and maintain
1he code.
• Debug Cneck the code for errors and fix the errors you find.
• Maintain Make changes 10 the code so tilat it can do new things, or
work better.
You will have learn more about debugging and maintaining code in ,he
rest of this unit.
I made a deliberate mistake In t11e oode and saw the error message
shown In Figure 8.3.5. The message told me where tne mistake was.
That helped me to fix the error.
/ ACTIVITY
I
1 Write ihe code shown on this page.
2 Make a deliberate error and no1e the error message 1hat appears.
Fix 1he error 10 debug your code.
3 Cnange 1he program so 1he code reads 'VBA program alert'.
---- --Figure 8.3.5
X
Input, processing and
output
LEARNING OUTCOMES
You have learned 10 write a
simple VBA program. I" 8.4,
you will tum an algomhm Into
a pr<>9ram. The program will
include input, processing and
output.
Translate an algorithm into a program
In Unit 7. you made an algorithm to work out pay by multiplying hours
worked by rate per hour. You expressed this algorithm as a flowchart
and using pseudooode. The algorithm is the same, bvt It is expressed In
two different ways.
Figure 8 .4.1 shows the flowchart version.
Here Is tne pseudocode version.
input Hours
input Pa,yRate
Fey = Hours • Pa;yRate
output Pay
Analyse the algorithm
Before you turn an algorlthm into a program, check h carefully.
[_____
s,.1a_r1_ _~)
f
/
Input Hou·s /
f
• What values must be input?
• What processing (such as calculation) is there?
• What values must be output?
The example algorithm includes input, processing and outpUT. Now you
will write a VBA program to match this algorithm.
Input Pay-ate
Start a new sub-procedure
Pay = H01Jrs • Payrate
You can delete tl1e 'Hello World' sub-procedure or leave it In place. Start
a new sub-procedure with this line of code:
Sub Pa;yCa.lc()
/
Outou: Pay /
f
(~_sio_o_)
Figure 8 .4.1
Siwp ~ Howcnart
VBA will add !he final line 'End Sub'. Type tne rest of ihe program
between these two lines.
VBA does not mind whether you use upper or lower case letters. It does
not mind whether you indenl code or not. But use clear capitalisation
and indentation io make your code more readable.
Inputs
The first line of the algorithm is
input Hours
The VBA command 'lnputBoxO' is t>Sed to input values to variables. The
value from the lnptrtBox will be assigned to a variable called Hours. Here
is tne command.
Hours = InputBox()
Remember tha, well-formed code includes a prompt to tell the user what
data to input. Add the prompt inside the brackets. Notice that in VBA we
ah,..,ays use double quote marks.
Hours = InputBox(" Enter flours Worked")
You know how to run source code. Run it now to see what it does. You
can enter a value into the box, as shown In Figure 8.4.2.
Add a second line to the program to input PayRate.
Mltwwft&.ml
Enter hours worked
Processing
I
Cancel I
OK
The next line of 1he algorithm shows the processing that Is needed.
Pey = Hours• PeyRate
This code will work perfectly in VBA so simply type that line.
Figura 8.4.2 I
Output
The final line of ihe algorithm is
output Pey
You have already learned to use MsgBox (Message box) to output a
value. Add this line to the end of the program.
Msg'Box( Pa;y)
ACTIVITY
Remember that well-formed code includes more detail in tne output
message. Include explanatory detail.
Msg'Box( "Total pay $" & Pey)
The completed program
The finished program should look like this.
Sub PayCalc()
Hours = InputBox("Enter hours v1orked'')
PeyRate = Input Box( "Enter rate of pey")
Pey = Hours • PeyRate
Msg'Box("Total pey is $" & Pey)
End Sub
Run this program.
• If you nave mistyped any part of the program you will see an error
message. Fix the error and try again.
• Try out different inputs and see what outputs you gel.
You VIAii iearn more aba.;t testing a program lo find and fix errors in 8.6.
Tne following pgeudocode
describes an algorithm to
calculate the tax that an
employee has to pay.
input Pa;y
Tax = Pey • 0 .2
output Tax
Create a program with a
5vilable name 1hat matches this
pseJJdooode.
Using what you have learned
make one program that:
• inputs hours and payrate
• outputs pay and tex.
LINK
Find out more about
Summary
The following table summarises everything you have learned so far.
For each type of command in an algorithm there is a matching VBA
command.
Flowcharts: 7.3
Algorithm command
VBAcommand
Extra notes
Input a variable
Variable = lnpJtBoxO
Add a prompt for the user Inside the brackets
Calculations
Variable = Calculation
To make the calcvlation use the same arithmetic
operators as in pseudocode
Output a variable
MsgBox(Variable)
Put any extra output message inside the brackets
%
Readability and variables
LEARNING OUTCOMES
You have turned an algorithm
into a working VBA program.
In 8.5, you will Improve ihe
program by making rt more
readable and by declaring the
variables.
Readability
Your program already nas many good features that make it readable.
• Identifiers such as the name of the sub-procedure and the variables
are well chosen to match the function of 1he program.
• Use o f indentation and spacing makes 1he program easier iO read.
To make the program mere readable, you can add comments.
Programmers add comments to explain w hat the program does.
Commenls are ignored by the computer. To slart a comment, type the
single quote mark. VBA w ill show all the words that follow in green .
Sub Pey()alc()
'Print greeting to screen
M sgBol('H ello World")
End Sub
Readability features are sometimes called 'lnlernal documentation', All
tne documentation you r eed is built into the program cod e.
Declare variables
Data type
Name In VBA
Boolean or
Logical
Bcolean
Integer
Integer
Real or Float
Single
Text
S1rlng
Figure 8.5.1
Declaring variables means setting out t1'e names and data types of
all variables used in the program. A well-formed algorithm w ill include
variable d eclarations.
In 7.7, you extended 111e Pay algorithm to include tne following variable
declaralions.
declare Hours as Integer
declare Pa,yRat e, Pay as real
In VBA, the word ' Dim' is used inslead o f ' Declare' . Each variable m~st
be declared on a different line.
VBA has ils own names for the d ifferent data types. These are shown in
1he table in Figure 8.5 .1.
VBA has olher dala types. One is ' Currency' . This w ill show a value
uslng exaClly ':l'IO decimal places.
Here is lne program. It has been improved by adding variable
dec larations.
Sub PeyCalc()
'Declare varla.bles
Dim Hours As Integer
Dim PeyRa t e As Single
Dim Fey as Single
'Calculate pa.v by multiplying Hours by Rate per hour
Hours = InputBox( "Enter h ours wor ked")
Pa,yRate = Input B ox ( "Enter rate of pa,y")
Pay = Hours • PayRate
MsgBox("Total pay is$" & Pay)
End Sub
Add a declara1ion section 10 your program. You oan change 1ne dala
1ype 'Single' 10 'Currency' if you like.
Advantages
The VBA program will still work witnovt the variable declara1ion section.
So why bother to add 1r,ese extra lines? There are several advantages 10
declaring variables:
• It makes the code run faster. The computer doesn't have to work
out what data type to use
• VBA will check your code for errors. If you enter i he wrong type of
data the compvter will spot your mistake and help you fix it
• The code is more readable. All the variables are se1 out clearly at
the start.
11 is so useful to declare variables tha1 VBA has got a special command
called 'Option Explicit'. If you put 'Option Explicit' at the lop of your code
It will force you to declare variables. If you try to use a variable wi'.hout
declaring it, you will gel an error message.
Declare constants
Remember that constan1s are used 1o store values that will not change
,,rnen you run the program . Suppose that 'PayRate' was $12.50 for all
employees. You would not need to ask the user to enter i ne value each
lime. You oould set this value as a constant.
ACTIVITY
1 Make 1he two versions of the
program shown on this page.
Run 1hem and check for errors.
2 Extend the program. Declare
a variable to store the
employee's name. Input the
employee name, and show
1he name iri the final outpvt
message.
Here Is an new example o' the program wfth some onanges:
• The 'Option Explici1' command has been added .
LINK
• PayRa1e is declared as a constant not a variable.
• The line w'nere 1he user input PayRale has been deleted.
Find out more about
• The variable Pay is 1he Currency da1a type.
Opt.Ion Explicit
Sub PayCalc()
'Declare constants
Const PayRate = 12.5
'Declare variables
Dim Hours As Integer
Dim Pay as Currency
'Calculate pey by multiplying HOUI'B by Rate per hour
Hours = InputBox( "Enter hours worked")
Pay = Hours • PayRate
MsgBox( "Total pay is $" & Pay)
End Sub
Variables: 7.2
('~
Finding and fixing
program errors
LEARNING OUTCOMES
You have written a VBA progr,l.m.
In 8.6, you wi11learn how to test
a progral"'l, find errors. and fix
them.
Program errors
All programmers make errors when they wrile programs. If you find
errors in your program this does not mean you are a bad programmer. In
fact, if you find and fix errors, that means you are a good programmer.
There are three different types of error. Each one Is found and fixed in a
different way:
• Syntax errors
• Run-1ime errors
• Logical errors.
Syntax errors
The rules of a programming language are called syntax. Sometimes by
mistake programmers write code tha1does no1 follow 1r e right syntax.
These are called syntax errors.
Syntax errors might include:
• spelling a word incorrectly
• using the wrong symbols as operators
• putting the words in the wrong order.
If your program has a syntax error, the computer will not be able to turn it
Into machine code. Tre computer will display an error message to show
you where the error is.
Run-ti me errors
You can fix all the syntax errors in a program. That means the compU1er
can turn tr,e source code Into machine code. But when the complfier
tries to run the machine code, It doesn't work properly.
Three ccmmon types of run-time error are:
• Try to divide by zero
• Data type errors
• Endless loop.
Divide by zero 11 is mathematically Impossible to divide a number by
zero. If you try to do this in a program, it will crash.
Data type error The data type of a variable shows what type of data it
can store. If you try to store the wrcng type cf data, your program may
crash.
Endless loop You have learned to make algorithms witn loops. Every
loop should have an exit condition. If the exit condition is missing, or
doesn't work properly, then your program can get stuck in an endless
loop. This is a commcn run-time errcr.
logical errors
logical errors can be the hardest errors
10 find and fix. If your pro:iram has logical
errors tt will run OK. But the program
won't give you the righ1 result.
For example, suppose the program was
supposed 10 deduct tax from salary,
bu1 Instead ~ added It. The computer
can't spot 1his problem. Only you - the
programmer - can tell tha1 !he program
Is producing the wrong result.
Every program must be 1horoughiy
1ested lo spot any logical errors.
Testing
Type of
error
What Is the effect of
this error?
How to find and fix the error
Syntax
error
Tre program w,11 no1
transla1e Imo machine
code.
Run-time
error
The program will start
to run but tt will crash or
get s1uck In an endless
locp.
The computer displays an
error message 1elllng you
where the error is. The
program will not run until you
fix all syntax errors.
Test the program with different
inpu1s to make sure nothing
causes the program to c,-ash.
Logical
error
Tne program seems 10
Figure 8,6.1
How to find and fix errors n prograrr-s
Carry out lots of tests and
work fine, but It give you check the ou1put In each
the wrong resutt.
case - did you ge, 1he result
youwarrted?
Testing a program means running the
program and entering different Inputs to make sure the program works
properly.
Every program should be thoroughly tested using a wide range of test
da1a. See 7 .14 for more informalion about suitable test data. You should
choose:
• Normal data
• Boundary data
• Impossible da1a.
Compare 1r e ovtputs of your program 10 the outputs you expect. If you
get the results you expect tnen your program has passed the lest If you
gel the wrong results, find and fix the error.
LINK
Find out more about
Testing: 7,13
Data checks: 1.1 4
/ ACTIVITY
This VBA program has all three types of error. Using all the methods ycu have learned,
find and fix the errors.
Opt.Ion Explicit
Sub CalcChange()
'Deola.re V&l'ia.bles
O!m Cos tAs String
Dim CashAs Currency
'This program Is for a supe:rma.rket aheck.out
'It works out oba.nge for the customer by
'Subtre.otlng the cost of goods from the ca.sh pa.Id
Cost = "$6"
Ce.sh = InputBox("Enter the amount of cash tendered")
Change = Cost - Ce.sh
MsgBox( ''Che.nge due $ " & Ce.sh)
End Sub
%
Making programs from
conditional algorithms
LEARNING OUTCOMES
You have learned 10 write error'ree programs in VBA In 8. 7, you
will learn to translate an algorithm
that Includes a ccndttional
structure ,nto a VBA prograM.
Conditional structures
In Untt 7, you learned about algorithms that include conditional
strvciures. In a ccndttional structure, the algortthm includes a logical test
The algorithm has alternative commands, depending on whether lhe test
is True or False.
Example algorithm
This example algorithm was shown in 7 .8. Now we will turn it into a VBA
program .
if Exam.Mark > 49 then
print " The pupil has passed the exam"
else
print "The pupil did n ot pass"
endif
It is very easy to turn this pseudocode algorilhm into a VBA program.
VBA code is very similar to pseudooode. It uses the same relational
operators and the same if•.. then ... else structure. The main difference is
that 'End If' is snown as two words in VBA.
If Exam.Mark > 49 Then
MsgBox ( "The pupil passed the exam")
Else
MsgBox ("The pupil ctid not pass")
End If
Here is the completed program.
Option Explicit
Sub ExamCheck()
'Declare variables
Dim ExamMark As Integer
'Input Exam Mark
ExamMark = InputBox( "Enter exam mark")
'pass mark ls 60
'dlsp]aor message to indicate whether pupil has passed
If ExamMark > 49 Then
M sgBox("The pupil passed the exam")
Else
MsgBox("The pupil has not passed")
End If
End Sub
Nested if structures
In 7.8, you learned that one ccndttio,ial s1ructure oan be 'nested' inside
another. Here is the example from that page.
If Exa.mMark > 49 then
if Exam.Mark > 79 then
I
174
print "Distinction"
else
print "Pass"
endif
else
print "The pupil has not passed the test"
endif
This algortthm can be turned into VBA with very little change.
The print command is replaced with MsgBox.
l
Input Number
Remalnder =
Number = MOD 2
Here is the completed program.
Option Explicit
Sub ExamCheck()
'Deola.re variables
Dim ExarnMark As Integer
'Input Exam Mark
ExamMark = InputSox("Enter exam mark")
'displey messl3€e to lndioate pupil grade
If ExamMark > 49 Then
If ExamMark > 79 Then
I\1sg'.Sox( "DJstinctlon")
Else
Msg'.Sox("Pass ")
End If
Else
MsgSox("The pupil has not passed")
End If
End Sub
Output
'Odd number'
Output
'Even number'
(~_
s _top_ ~ )
Figure 8.7.1
Conditional flowchart algorithm
So far, the examples in this unit have converted pseudocode algorithms
Into VBA code. This example uses a 11owchart algorithm.
Figure 8.7.1 shows an example flowchart. A number is input and the
MOD operator is used to 1ind the remainder when the number is divided
by 2.
Looking at this flowchart, we can see:
• the logical test is 'Remainder = O'
• i1 the tesl is True the output is 'Even number'
/ ACTIVITY
I
, Tum the fc11owing pseudocode
algorithm imo a VBA program.
Input number
if number> 0
print "positlve''
else
print "negative"
endlf
2 Write a VBA program that
inputs two numbers and prints
out the larger number.
• i1 the test is False the output is 'Odd number'.
Here is the start of a VBA prcgram built from tnis flowchart. Can you add
the commands needed to complele the program?
Sub OddEven()
'declare variables
Dim Number As Integer
Dim Remainder As Integer
'calculate MOD
Number = InputSox( "Enter Number")
Remainder = Number Mod 2
End Sub
LINK
Find out more about
Decision boxes: 7.L
Conditional sin..ctures: 7 ,8
Arithmetic and logical
operators: 5.2
%
Making programs with
loops
LEARNING OUTCOMES
You have learned 10 write
programs i" VBA using
oonditional structures. In 8.8, you
wlll leam to translate an algortthm
that Includes a loop inlo a VBA
program.
Loops
A loop oontains commands !Pat are repeated. Every loop must have an
exit condition. The exit condttion is what Slops !t:e loop. There are three
types of loop: a for loop, a while loop and a repeat until loop. All three
types of loop can be used in VBA programs.
For loop
You saw how to write pseudocode algorithms with for loops in 7 .9. This
pseudocode algorlthm adds up the total of ten numbers.
KEY TERMS
A for loop Is also called a
counter-controlled loop. Tre
counter oounts up from one
number to ano:her. That sets :he
number of loops.
A while loop is a condition-
controlled loop. It includes a
logical test. If ,he test is true 1he
loop C::ontln~es. If :he test Is false
tre loop stops.
A repeat until loop Is a
condition-controlled loop. It
Includes a logical test. tt the lest
1s true tl'e loop oo~tirues. I' tl'e
test is false !he loop stops.
Total = 0
for l = O to9
input Number
Total = Total + Number
next i
print Total
Here is the algorithm oonverted into VBA.
Option Explicit
Sub AddUp()
'Deola.re variables
Dim Total As Integer
Dim Number As Integer
Dim 1 As Integer
'Add five numbers to Total
Total = 0
For 1 = 1 To 5
Number = InputBox( "Enter Number")
•rota.I = Total + Number
Next i
MsgBox("Tota.l is " & Total)
End Sub
The oounter is a variable of integer data type. Remember to declare
the counter variable along with all the olher variables al the top of the
program.
While loop
You learned about while loops in 7.1 0. A while loop is controlled by a
logical test. If the test is true, the loop repeats. Here is an example of an
algorithm that uses a while loop.
input Pass11rord
,vb.He Password <> "Sesame"
output "Incorrect password, try agatn•
input Password
end ,vhile
output "Correct Pa.ss,•1ord"
This loop algori!hm can be turned inlo a VBA program. Notice that
'while' in the algortthm becomes 'Do Wliile' in VBA Also. 'Loop' is used
instead of 'end while' in VBA. Here is the comple1ed program.
Option Explicit
Sub PassCheck()
'Deolare variables
Dim Password As String
'Enter Password until oorrect
Password = InputBox("Enter Pass\vord" )
Do While Password <> "Sesame"
Pas sword = InputBox("Incorrect, try again")
Tota.I = Total + Number
Loop
Msg'.Box("Correct passv,ord")
End Sub
Repeat until loop
The following algori!hm will find lhe smallest number in a list. Tne loop
stops when 1he user enters a number bigger than 99. This algorithm
uses a repeat llntil loop, with a nes1ed 'if' .
Smallest = 100
repea t
Input Number
if Number < Smallest then
Smallest = Number
endJf
un til Number > 99
pr in t Smallest
In the algorithm, the loop starts with the word 'repeat'. In VBA this
changes to 'Do'. In 1he algorithm, the loop ends with the word 'until'.
In VBA we change this to 'Loop Until'. Here is the completed VBA
program.
Option Explicit
Sub FindSmallest()
ACTIVITY
1 Wr~e a VBA program using a
•or loop to print ol.ll the 6 times
1ablefrom 6 x 1 to 6 x 12.
2 Write a VBA program using a
While loop to find 1he average
of a series of numbers. The
loop will end tt the user enters
a negative number (below 0).
3 Write a VBA program using a
repeat un1il loop to coun1 how
many even numbers there are
in a series of numbers emered
by the user. The loop will end f
1he vser enters the value 0.
'Declare varial>les
Dim Smallest As Integer
Dim Number As Integer
'Enter a series of numbers to find the sma.llest
Smallest = l 00
Do
Number = InputBox("Enter a number")
If Number < Smallest Then
Smalles t = Number
End If
Loop Until Number > 99
Msg'.Box("The smallest number ls" & Sma llest)
End Sub
LINK
Find out more about
Loops: 7.5
For loop: 7 .9
\IVhile loop: 7.10
Types of oo<'dittonal loop: 7.11
C\)
Reading data from a
spreadsheet
LEARNING OUTCOMES
You have learned how to make a
program 1fla, reads input typed
by 1he user, In 8.9, you will learn
how to take input from :he cells
of a spreadsheet.
Input data from a spreadsheet to a variable
You have been using a version of VBA that is attached to Excel - the
Mietosoft spreadsheet application. But your programs do not use
spreadsheet data. Now you will write a program that does use dala from
a spreadsheet. This means that you do not have to type in data when
you run the program.
For example, here is a spreadsheet tha1 is used in a restaurant to store
1he customefS' food orders.
A
1
2
3
4
5
Rice and peas
Beef patty
Jerk chicken
Roastyam
Curry chicken
•
C
Figure 8.9.1
Type this data Into your spreadsheet Or you can type any other food
items that you like. Now yov will write a program 1hat displays the
kitchen orders so the cook knows wha1 food item 10 prepare next.
Read data from one cell
The first hem is 'Rice and peas'. This is s1ored in a cell. The cell is
row 1 and column 1 of the spreadsheet.
This command will take the value from t11e cell in row 1, column 1. It will
assign 1he value from 1hat cell to a variable called Menultem.
Menuitem = Cells( l ,l )
Here is a completed program that reads and displays the value In
cell 1,1.
Sub KltchenOrder()
Dim Menuitem As String
Menuitem = Cells(!, l)
MsgBox ( "Kitchen order: " &! Menuitem)
End Sub
Before you continue, create this program and run it to see what tt does.
Read data from a group of cells
To make the Kitchen Order program more useful we will change it so
1hat il reads every nem in tne list. To do this, we will use a loop structure.
There are exaClly five items in the list so we will use a counter-controlled
loop that counts from 1 to 5.
All the items are in column 1, so the column number will not change.
But the items are in different rows, so we w1ll use l he counter variable to
count through the different row numbers.
Forl=lto5
Menultem = Cells(!, 1)
MsgBox ("Kitchen order: " & Menultem)
Next i
Make this program now - remember lo declare Menultem as a string
variable and the counter i as an integer variable.
Use a conditional loop
Suppose you did not know how many items there were in the lisl. For
example, the waitress might be adding new items all the time. In that
case, you could use a condition-controlled loop. It would read tne list
until It reached an empty cell.
ACTIVITY
The spreadsheet in Figure 8.9.2
contains the register for a maths
group in a school. Copy this or
make yol.lr own list of names,
Tne maths teacher wants a
program 10 display the students'
names one by one. Wrile a
program for the maths teacher
that reads through the list of
names and displays them one by
one on the screen.
Here Is a version of the comple,ed program, using a repeat until loop:
Sub KitchenOrder()
Dim Menultem As String
Dim i As Integer
i= 1
Do
Menultem = Cells(!, l)
MsgBox ("Kitchen order: " & Menul tem)
i =i + I
Loop Until Cells(!, 1) = ""
MsgBox ("No more food orders")
End Sub
Notice that because this is a conditional loop not a counter loop, you
must add a command to increase the counter variable i by 1 with each
iteration of the loop. Try making a version of this program using a while
loop instead of a repeat until loop.
Current spreadsheet
Unless you tell it otherwise. the program will read data from the
spreadsheet tna1 Is open on your screen.
B
A
• Selena Brown
2 Joel WIiiiams
3 Dominic Smith
4 Christen campbell
5 Brandon Johnson
6_ Gabnel Thompson
7 Kyle Clarice
8 Victoria Reid
9 Claire Grant
.,,
Figure 8.9.2 I
I
Working with an array
LEARNING OUTCOMES
A variable is a named f"lemory
location. You have learned to
assign a value to a variable. Each
variable slores one data value.
In 8.10, you w,11 leam to use an
array. An array Is a way :o store
a series of data values Instead of
Just one.
Note: Working whh an array is not on the syllabus: however, It is useful
extension material.
What is an array?
An array is a type o1 variable tnat can store a list of different data items.
Each data item is called by the name of the array plus a number in
bracke1s. All the data Items in the array must be the same data type. In
8.10, you will make a program that stores a list of cities.
Declare an array
All variables must be declared before they are used. You have to give
each variable a name a~d a data type. When you declare an array, you
also need to say r ow many data items it will hold.
For example, this statement will declare an array called Cities. Toe data
items are string data type. We will make an array that stores the names
of five cities.
Dim Cities ( l to 5) as String
Structure of an array
The data Items in an array are called 'elements· of the array. The Ci!ies
array has five elements. They are called:
Cities( I)
Cltles(2)
Citles(3)
Citles(4)
Cltles( 5)
The elemenls of the array are identical except for the number. The
number is called the index.
Input data to an array
When you firsl make an array, all 1he elements are empty. You can write
a line of code tnat will assign a value to one element. Remember to give
the index number. This example assigns a value to elemeni 1 of the array.
Cities(!)= "New York"
Or allow the user to input a value to the data Item. This example assigns
an Input value to element 2 of the array.
Clties(2) = InputBox( "Type the name of a city")
But usually ycu want to assign values to all the elements o1 the array. The
easiest way to do this is 10 use a oounter-controlled loop. The counter
variable can be used as the index number. It goes up by one each 11me.
Fori = lto5
Oities(i) = InputBox("Type the name of a city")
Next 1
Filling up an array with data values is called ' populaling ' the array.
Make a program that declares and populates an array. Use the Cities
example shown here. er any o tner array thal you like.
Output an array
Now the elemen1s o f the array hold dala values . You can output a single
element using MsgBox.
MsgBox(Clties( l))
Bul what ff ycu want to output all the elemenls in an array? A counlercontrolled loop will ccunt tnrcugh 1he whole array, and o l.llpul each
element in turn.
Forl = l to 5
M sgBox( Clties(i))
Next I
Make a program that declares and populates an array and t11en outpuls
all lne Items.
Search an array
I'ACTIVITY
Prcgrammers often need lo search through an array.
• First d eclare and populate the array.
• The user enters a ' search item'.
• The program looks lnrough the elements of lhe array one by one.
• A logical 1es1 checks whetr er lhe element malches the search ttem.
• If the p rogram finds the item It outputs the message 'item found'.
Once again, a counter-controlled loop is lhe ideal way to work with an
array.
Searchltem = InputBox("Enter a search I tem")
Fori =l to5
If Cities( i) = Searohi tem then
M sgBox( "I tem found")
End.if
Next i
And finally, we can extend the program so that ff tr.e item is NOT found,
a message is displayed. To do lhis, use a Boolean variable thal stores
True or False. depending on whether the item was found .
In the program below, the new lines are shown In bold text.
Searchltem = InputBox("Enter a search Item")
Found = Fa.lse
Fori =l to 5
If Cittes(i) = Search l tem then
MsgBox("Item found")
Found = True
End.if
Next i
If Found = False then
MsgBox ("Item NOT found")
Endif
Make a program rnat:
1 Declares an array called
Stvdents with tenelemems
2 Populates l he array witn user
input
3 Outputs the elements
4
Searches the array for a
name entered by lhe user.
SECTION 1: Multiple-choice questions
Questions 1---5 refer 10 the ioilovvlng VBA program.
c
Decision table
Dim i As Integer
d
Flowchart table
n=O
Forl=lTo3
n =n + 1
Next i
1 \/\/hat s1ructure Is used In this program?
a
Conditional structure
b Counter-controlled locp
c
Condition-controlled loop
d
Logical 1est
2 11\/hat data type would you chOose for 100
variable n?
a $;ring
b
c
Boolean
Integer
d Conditional
3 How many times w,11 ,he loop repeat?
7 A'ter lhis line of VBA code is carried out, whal
value is stored In lhe variable ltemCost?
ItemCost = Cells(l ,6)
a A value taken from a spreadsheet
b The string "Cells{1,2)"
c Tre con1ents of element 5 in 1he array Cells
d Tne numbers from 1 to 5
8 An algorithm included lhe tine 'a= b + c'. Tnis is
an BX<1mple of:
a Variable declaration
b
Input
c
d
Processirig
Oulpu,
9 Al what stage o' 1ne programming process is
lhe program converted 10 machine code?
a
1
a Wnen 1re source code is written
b Wnen 1ne program is compiled
b
2
c
C
3
d W,ien 1ne program is executed
d 4
1 o 11\/hat does '.he following code do?
4 What line would you add to the end of the
For l = 1 to 10
Result(!) = InputBox("Enter result")
Next 1
program to print out the value of n?
a MsgBox{n)
b n = lnputBox("En:er the value of n')
c Print n
d n = Print
5 11\/hat Is the output of this program?
When 1he progr<1m is 1esled
a Ovtput an array
b Declare an array
c
d
Search an array
Populate an array
a 3
b 0
C
1
d 6
6 A programmer 1esls an algorithm using a dry
run. The vah.;e of each variable is stored in a
table. Whal is 1he name of i h,s table?
a Trace 1<1ble
Further praclice questions
and examples can be found at
www.oxfordsecondary.
b Truth table
oom/9780198437215
SECTION 2: Structured questions
1 \/Vrlle a complete VBA program to match 1he
following pseudocode algorithm:
Read Cost
Read Price
Profit " Cost - Price
Print Profit
4 Explain the 1hree main types of error that can
affect programs, and how you would de1ect and
fix eacn type.
2 Describe methods a programmer can use lo
make lier program more readable.
3 Rewrtte the 'allowing VBA program so that tt
uses a while loop:
Sub GuesslngGame()
ConstRlghtAnswer " l 0
Dim Guess As Int.eger
Do
Guess " InputBox("Guess the number")
If Guess > 1O Then
Msg:Box ("Too high'')
Else
If Guess < l O Then
Msg:Box ("Too low")
End If
End If
Loop Until Guess " l 0
Msg:Box ("You guessed It'')
End Sub
Further practice questions
arrd examples can be found at
www.oxfordsecondary.
oom/97801ga43721s
Access Computer access to
storage means tnat there is a flow of
data between the CPU and storage.
Tne CPU can take data from storage
('read access') and out new data
Into storage ('write access').
Access speed How quickly the
prooessor can read data from
storage.
Algorithm An algorithm is a way of
setting out t11e steps of a solution as
a sequence of instructions.
Applications software Applications
software enables the computer
iO perform some add~icnal useful
function. An example would be
Microsoft Word, which allows you to
create documents.
a
Backup A backup is a copy of all
your data, s:ored away from your
computer in a safe place. If there
is any kind of disaster and your
data are lost. you can turn to your
backup. Bringing back data from
backup is called recovery.
Binary Binary numbers are written
In base 2. They are made of only
two digrts (0 and 1).
Biometric Biometric systems
recognise a person's physical
characteristics, for example
reading their fingerprints or iris (eye)
scan. They are mainly used for
security purposes, for example to
allow access to banks or milltary
premises.
Array An array is a group of
variables. Each variable nas the
same name, but a different index
number.
ASCII ASCII Is a system for coding
text characters as numbers, so
they can be stored and processed
within the computer. ASCII stands
for American Standard Code
for ln/ormation Interchange. It is
pronounced 'Askey'.
storage can be accessed nght
away. A DVD is an example of direct
access.
di
Flowchart An algortthm can be
represented by a diagram called a
flowchart. A flowchart coflSists of a
series o' boxes joined by arrows.
a
GUI T11e Graphical User Interlace
(GUO is how the computer allows
you to see informalion and give
Instructions 10 the computer. It
makes t>Se of a mouse, icons,
windows and a pointer.
Hardware Hardware is a general
Arithmetic operators Arithmetic
operators are symbols that allow
you to periorm mathematical
processes. Examples are: - and +
and• and /
Direct access Any part of :he
Capacity The capacity of s:crage
ls how much data it can hold.
Compiler A compiler is a piece
of software that takes a program
written in a high-level language and
turns tt into Machine Code.
CPU The Central Processing
Unit of the computer. This Is the
hardware component in which
processing takes place.
d
Data A collective term for facts and
figures of any kind.
Assembly language Assembly
Data integrity means making sure
language is a code of three-letter
words that represents Machine
Code but is easier 'or humans
to read. It can be converted to
Machine Code using an
assembler.
thal data are not spoiled, changed
or deleted.
Data security means keeping data
f
k'
sa e. 1I a1so ';'eans ma ing s~re
data
and no. read
"h are
,,. kep,,pnvate
.
w.. ov, perm1ss1on.
lerm for all the pieces of equipment
that make up a computer system.
In general, any part of a computer
system tnat you can touch or carry
Is an ttem of hardware.
Hexadecimal Hexadecimal
numbers are written in base 16.
As well as the digits 0-9 they use
the letters A-F to represent the
numbers 10 to 15.
High level language A nigh-
level language is a method of
creating a computer program that
is easier 10 use and more flexible
lhan assembly language. II can be
converted lo Machine Code using a
compiler.
d
· d t
Inpu t Inpu t means 1urr11ng
aa
and inslructions into electronic form
so lhey can be processedby lh e
computer.
Interface The connection between
any two systems or parts which
allows lhem to communicate.
Secondary storage is connected to
the processor via an interface.
Internet Tne imernet is a global
network of computers. It is not run
or controlled by anyone.
d
Logical operators Logical
operators allow you to combine
yes/no statemenls to give a
sta,ement which is either true or
false. Examples are: AND and OR
and NOT.
d
Machine Code Machine Code
is the binary number code ,hat
comp:.rters use lo Slore instructions.
Network A oomputer network is
oompuler processes da1a to create
useful in'orrnation.
Protocol A communica1ions
protocol is an agreed set of rules
and signals that control hovv signals
are senl. If two compulers are using
the same protocols then they can
share information.
Pseudocode Pseudocode is a
formal system of written ins1ructions
that is similar to a computer
program. It is a way of setting
oul an algorithm and planning a
computer program before ceding
begins.
d
RAM Random Access Memory.
RAM is read-write memory (which
means it can store new data).
RAM is volatile. which means tt
the computer is switched off, or
the electricity goes off. all the data
stored in RAM will be lost.
any system that allows computers
to send signals to other oomputers
In electronic form.
cannol Slore new data. It is fixed.
Non-volatile storage Non-volatile
can be changed to store new data.
storage does not need electricity. It
holds data even when the computer
is turned off.
Output Oulput means turning
data held in electronic form within
the computer system into a form
that people can understand or use.
d
Processing Processing mea,'lS
changing data, for example by
ordering tt, sorting it, transfon11ing
it or carrying out calculations. The
Read-only memory Slcrage that
Read-write memory Storage that
Relational operators Relational
operators are symbols that allow you
to compare two values. Examples
are: < and > and <> and =
ROM Read-Only Memory. ROM
stores the instructions to start
up the oompuler system. These
Instructions are fixed In tne factory
where the computer was built.
Sequential access The Slored
data can only be accessed in order.
A video tape is an example of
sequential access. Access is slow.
Software A collection of
instructions, intended to produce
a particular result, is called a
computer program. Software Is the
general term for these instructions.
Storage Storage in a computer
system is the retention of data in
electronic form ready tor tne CPU
to use.
Systems software Systems
software controls the operation of the
computer itseff. An example would be
Microsoft VvindQ1,vs, which allows you
to work with your oompu!er files.
d
Top-down design Top-down
design is a method of computer
programming where the work that
nas to be done by the program is
broken down Into small modules.
Validation Validation is a check
that the data entered into a
computer are valid. 'Valid' means
the data are of the right general
type or value.
Variables Variables are named
areas of computer memory. You can
store any value in the variable, and
t11e value will be available when the
variable name Is used.
Verification To 'Verify' means 10
double-check l hat somelhing is
true. For a verification check the
dala iPput is carried out lwioe - for
example, a password is typed twice.
The computer checks lhat the two
versions are exactly the same.
Volatile storage Volatile storage
uses electricity. If the el~ ricity is
rurned off, the data disappear.
:
A
absolute ce I re'.erences 99, 100- 1
access 10, 30· 1
administrators 56-7
algorithms 13~, 135
dear outputs 147
condition-controlled lccos 152- 3.
154-5
conditional structures 148-9
ccunter-control/ec loops 150- ·
data types 146- 7
make your a'gorlthm readab e 146
maldng p1cgrams f1om conCitioral
algorithms 174
prompts to the user 147
pseudccoce algorithms 1a+5
testing 158- 9
cransiate an algorithm ln;o a progiam
168- 9
well-formed pseudocode crogram 1''7
ant:•virus software 47
appl'cat'ons software 16. 17
ar th met c operators 90. 137, 1S6
arrays 180
artificial intel ,igence (Al) 53
assembly language 162- 3
assisted drlv,ng 52
aud'o output 15
autom isation 3
autonomous vehicles 52
8
backups 47,48, 49
bandwidth 35
bar charts 110
bias 46
binary 9
binary data 9
biometric systems 13
bits 9
B uetooth 3$
brackets 93
bridges 36
broaccast comm1..inicatlon 35
bytes 9
C
CADD (computer-aided design and
draft'ng) 52
CAE {comouter-aiOed engineer'ng) 52
ca culations 92- 3
CAM tcomou;er·a·cea manufar:turing) 52
caoacity 10
cel ls 97
character formatting 61 , 96
characterreaders 13
citations 26
clock speed 20
cloud cornpu:lng 53
clocd storage 11, 21
colcmns 63, 67. 97, 103. 113
comrrerce 3, 41, SO
communication terms 35
computer fraud 47
computer systems 4
ccrrpurer hardware 4- 5
evaluating 20- 1
lns·ce the CPJ S
main functions of a comouter system 4
security measures 47
~roes of corrputer system 6,-7
condition-controlled 'oops 152-3, 154
conditional loops ·, 79
conditional sta:ements 14C- 1
conditional structures 148-9, 174
conditional flowchart algorithm 175
nested 'f structures 17"-5
constants 137
declaring constants 17 1
Copy and Paste 6 1
spreadsheets 98- 101
counter-control 'ed loops 150- 1
CPU (Central Precessing Unit) 4, 5
crirre 45
cursors 60
D
data 4, 9
spreadsheets 89
us'ng forms to collect oata 7•
data checks 29-1 0 1
data encrypt,on 47
da:a entry forms 126
helcful fea:ures 127
va 'idaticn checks 126
da:a files 30
fie organisation and access 30- 1
storage rreola 30
use of oiflerent Ale types 31
data integrity 49
da:a misuse 46- 7
bias and persuasion 46
counter measures ~1
!'legal copying and computer fraud 47
privacy and security 46
data process;ng 24·5
da:a security 49
da:abase repor:s 130·1
databases 70, 118
ad hoc queries 120
create and use a oata entry form 126-7
creating and amending 124- 5
data lnoul technology 127
data types 119
database design princic 'es 120, 122- 3
datasheet entry 126
DBMS 124
felds 119
key lie !ds 119
one-to-many 123
popu 1ate and use a oatacase structure
125
query forms 129
records 119
rela:ional databases 122- 3
rela:ions between tables 123
sea'ch criter'a ·, 28-9
searching 128-9
see the database structure 124- 5
taoles 118
transact ,on processing 127
types of search 129
use of identi'ying keys 120- 1
what are databases for? 120
DBMS 124
desktop computers 7
d.rect access 10, 31
division 137
document structure 64-7
documents 25
domain narr.es 82
driving 52
duplex comrrunication 35
E
eciting text 60- 1
education 4 1, 50
embedded dev;ces 7
emerging technologies 52- 3
endnotes 65
engineers 57
emer:ahment SA.
Ethernet 37
Excel 164- 5
expert systems 52
F
~e,as 104, 11 9
orlmary ano seconoary sort field 105
use of Identifying keys 120- 1
file servers 37
liles 30- 1
file transfer 38
uploading to a web page 83
FII 98
lillao 'e forms 74-5
f ,lter 106
complex criteria 106- 7
Find 69, 106
lirewalls 47
f •owcharts 138·9
footers 65
footnotes 65
for 'oops 151,176
forn"atting database reports 130
formatting spreadshee:s 96- 7, 113, 115
formatting text 60- 1
forms 74-5
'ormu a 92
FTP (fi e Transfer Protocol) 83
functions 94·5
G
gigabytes 9
governments 45
graphics cards 20
graphs 110,1 31
GUI {Grap~ical User Interface) 18
'eatures of a Graphical User nterface
(GUI) 19
H
half-<:lup ex commun cat'on 35
hard drives 11
haroware 4-5, 5
haroware problems 22·3
headers 65
hlgn-level languages 163
H1ML 80
hubs 36
IF function 108
!oglcal :est 108
value if true, value if fa'se 108-9
il 'egal copyir.g •7
Images 13
Importing graph'cs and other items 66,
11 2
indents 63
Indexed sequent al access 31
Industry 2- 3, 51
informat on manage'Tlent 3
Information onllne, reliability 26- 7
lnfo,,,,at on retrieval 3
input 4, 12, 168-9
data process ng 24-5
,nput a value to a variable 145
,nput data an array 1eo-1
;nput data from a spreadsheet to a
variable 178
,nput dev'ces 21
;nput 'mages 13
,nput 'etters and numbers 12
,nput sounds 13
nputto a database 126- 7
other types of input 13
po'nt-and-d:ck 12- 13
Integer division 137
Interfaces 10, 11, 18- 19
Internet 38·9
Interoperability 112
Intrusion detection systems 47
IP (internet Protocol) 37
IP addresses 82
J
Jobs 45,55-7
K
key fields 119, 120- 1
keyooards 13
kilob)1es 9
low-level languages 163
M
machine code 162, 163. 167
Mail merge 70-1
mainframe computers 6
malware protect on 49
manufacturing 5 I
mechan·sation 3
media 54
medicine 51
megab>1es 9
memory 8. 9. 20, 21
microprocessors 7
mobile communication retworks 40· 1
mobile computer devices 7
modems 35
mult -core processors 20
multmedia artists 57
N
net'works 34, 35-7
news 54
non-volatile storage 8, 9
numbers 12
0
on 1ine communication 39
on!ine information 26-1
operating systems 18
features of a Graphical User Interface
{GUI} 19
~ser ·nterface 18- ·,9
operators 90
arithmetic cperators 90, i 37, 156
logical operators 90, 91, 128-9. 156
relational operators 90- 1, 128, 140. 141,
i 56
L
law· enforcement 50
leisure "1.51
letters 12
line graphs 11 O
line Just,lication 62
line spacing 62
links 81 , 83
lcg!ca errors 173
logical operators 90, 91, 128-9, 156
ANO 156-7
NOT 157
tr~th tables 157
leg cal tests I08, 140, 148
loops 142,1 50, 176
condition-controlled oops I52
conditional loops 179
control 142-3
counter-controlled loops 150- 1
fcrloops 15 I, 176
'fthetest istrue 153
iteration 150
'"lestec structures 151
repeat until loops 154, 176, 177
rules of cond'tlon-controlled Icoos 152
types of loop 150
vvhen to use a condition-contro:!ed
loop 152
wh'le loops 152- 3, 154, 176, 176-7
you must be able to change the
variable 153
ou,put 4, 14-1 5, 147, i69
dat<> precessing 24-5
o.ataoases 129. I 30- 1
output a value to a varia:;: •e 145
output an array 181
output oevices 21
p
paragraoos 63
persoral computers 7
persuasion 46
pie charts 1 1O
pivot tab ,es 114-5
plotters 15
point-ano-cllck 12- 13
po ·rit·to-point cc~muiiication 35
pointers 60
'power of' 92- 3
print ser.ters 37
primers I"-I 5
privacy 46
problem solving 134
algorithms 134, 135
break·ng down a oroblem into parts
135
steps of problem so ivlng 134- 5
iestiog 135
process control 2
process ;r g 4, 169
o.ata processing :14- 5
processing speed 20
program cevelcpmen: 166
create source code 166- 7
current spreadsheet 179
debug and rraintain 167
dec :areconstants 171
declare variao 'es 170-1
execute orrun the program 167
finding and iixlng errors 172- 3
input data ~om a spreadsheet to a
variable 178
Input processing and oulput 168-9
making programs from conditional
algorithms 174
rraklng programs with loops 176- 7
read data f·om a group of cells 179
reac data from one cell 178
readabilty 170
sub-procedures 166
transla:e Into machine code 167
use a conditional loop 179
\"Jerking 'f.' ;th an array 180
o•cgram errors 172
logical errors 173
run-tlrre errors 172
syntax errors 172
test ng 173
programmers 56
o•cgramming languages 162-3
protocols 38
FTP (File Transfer Pro,ocol) 83
netwcr< pro~ocols 37
wire,ess protocols 35
pseudocode 144, 147
keywords 144
varlaO es 144- 5
publishing a web page 82- 3
R
RAM (Random Access Merrory} 8, 9
random access 31
read-on'y e
read·v-.,-rite memory 8, 9
readability 146, 170
reccros 104, 119
recovery systems 47, 48
referencing 65
relat'ona ' operators 90- 1. 128, 140, 141,
156
remote control 13
repeat unt I !oops I 5", 176, 177
robots 52
ROM (Read-OnlyWe'Tiory} 8, 9
routers 36
rows 97, 102- 3
n.,n-rme errors 172
s
schools 54
science 3, 51
searcning 69, 107, 128- 9
search an array !S i
secur:()' 46, 47-9
semi-autonomous vet:ic 1es 52
sensors 13
sequential access 10, 31
serial access 30
sl~plex ccmmunica~icn 35
smart objects 53
so,,al media 44
scftvvare 16, 21
applications softv,are 17
DBMS (Database Wanagement System)
124
general purpose software 17
interoperability 112
network software 37
software interface 19
software security 47, 48- 9
software tra·ners 57
systems software 16-1 7
web pages 80
sorrng spreadsheets I04- 5
sounds 13
source code 166- 7
spell check 69
spreaosheets 88
brackets 93
calculations 92- 3
cell references 93, 109
column w'oth 11 3
Copy ano Paste 98, 10 1
copying a formula 98- 9
cata formatt ng 97
entering data 89
extracting information ~om 106- 7
FIi 98
Filter 106- 7
Find 106
forma:tlng 96- 7, 113
formula 92
freeze columns I 03
freeze ro1,•,·s 102-3
functions 94-5
functions cf a spreadsheet 88
how to lock or split 103
IF function I 03-9
images and C ip art 11 2
impor:lng toa spreadsheet 112- 13
insert items 11 2
mu ;lple worksheets 109
number formatting 96
operators 90- 1
pivot tables 11"-15
power of' 92- 3
program oeveloprrent 178- 9
range of cells 89
recoros and Belds 104, 105
relative eel, references 99, 1CO- I
rows, columns and cells 97
search funct'ons I 07
sorting 104-5
split w·ndows 103
spreadsheet graphs 110- 11
struccure cf a spreadsheet 88-9
tables 112- 13
templates 113
text formatting 96
usage 99
use of fcrmatt:ng features 97
what Is diso 'ayed1 96
square roots 94
SSD (Sord-State Drive) 21
storage 4, 5
primary storage 8- 9
secondary storage 10- 11. 21
storage media I 0, 30
SUM 95
super computers 6
sw:;ches 36
syntax errors 172
systems analysts and designers 56
systems software 16, 16- 17
T
table ofcortents 72-3
tables e6- 7, 112- 13
tabs 63
TCP ;Transmission Control Protocol) 37
technicians 57
teiecommut ng 55
templates 11 3
terabytes 9
testing algorithms 158- 9
testing orcgram errors 173
text 60-1
coaracter formatting 61 , 96
::omrr,ents 69
Insert and de'ete text 60
move ano copy text 51
sa'ety features 68
search anc replace 69
s~II check 69
text layout 62- 3
text wrapping 62
track changes 68
\vord count 69
working with blocks of text 61
see document structure
thesaurus 69
three-dimens,onal printing 15
tm,monalls 81
trace tabies , ss . .9
translating an algorithm Into a program
168
analysing tne algorithm 168- 9
completed program 169
incu,s 168- 9
output 169
processing 159
start a new sub-procedure 168
summary 169
transmission media 34
truth tables 157
tuples 119
u
user Interfaces 18-1 9
V
validation 29
values 108-9. 136- 7, 139
variab 1es i 36, 144
arithmet'c operators 137
arrays 180- 1
assigning values to variables 136- 7,
145
constants 137
data rypes 146- 7
declaring variables 136, 170-1
input a value to a variable 145
nput da:a from a spreadsheet to a
variable 178
integerd iviS:on 137
loops 153
naming i 36
output a va,ue tc a variable 145
sequence of commands 145
VBA (Visual Basic Applicat'ons) 164-5
vehicles 52
verification 28- 9, 29
virus protection 49
viscal display units 14
vo 1atile storage 8, 9
w
wearable techno 1ogy 53
weo browsers 76. 83
web page address 77
weo pages 76
des'gn and layout 81
enter text and images 80
find ng the right page en a sl:e 79
home page 79
HTML 80
1P address 82
links 81,83
oublisning a web page e2- 3
•eglster a doma n name S2
software 80
testing the page 83
tocmbnails 81
uploading content 82- 3
1
Neb servers 76
websites 77
audience 78, 83
design and layout 79
nosting ser1ice 77, 82
pages 78- 9
purpose 78
while 1oops 152- 3, 154, 176, 176- 7
Wi-Fi 35
1
Nireless connections 35
word count 69
word processing 60
como'nlng and m.erging 66- 7
creating a table of contents 72- 3
docuroent structure 64- 5
editing and formatting text 60- 1
he lpful features 68· 9
text layout 62- 3
using forms to col 'ect dat,; 74- 5
Words 9
work 4 1. 45
comouters at scnool 5-4
compu:ers :n the office 54
toss of Jobs 55
meoia, nev,1sand entertanmen\ 54
reuaining 55
te eccmmur ng 55
World Wide Web (WWW) 39
Study Guide
Less Stress, More Success
Developed exclusively wi th the Caribbea n Examinations Council"', t his Study
Guid e provides the support to help you maxim ise your performance in
Information Technology at CSEC" .
Wri tten by experts In t he CSEC" In formation Technology syllabus,
exam in ation and teaching, th is easy-to-use Study Guid e covers all t he
essential In forma tion you wi ll need for success In your examination.
• Build your confidence wi th exami nation -style practice questions
• Develo p the analytical skills required for t he exam ination
• Succeed wit h essenti al advice and examination tips
• Expand your knowledge with 'Did You Know?' boxes
Su pport your revision with multiple-choice and
examinatio n-style questions plus sam ple answers vvith
examiner's feedback. Go to:
www.oxfordsecondary.com/9780198437215
The Ca ribbea n Exam inations Council (CXC• ) has worked exclusively wit h
Oxford University Press to produce a series of Study Guides across a wide
range of subjects at CSEC" and CAP E<t.
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