om
.c
s
er
ap
eP
m
e
tr
.X
w
w
w
Scheme of work – Cambridge IGCSE® Computer Studies (US) 0441
Unit 5: Programming concepts
Recommended prior knowledge
Students need to have studied Units 3 and 4 before starting this unit.
Context
Students need to study this unit before or alongside Unit 12. It progresses from representing algorithms as program flowcharts in Unit 4, to representing algorithms
as pseudocode. For both Units 4 and 5, together with Unit 6, Computer Studies Support Booklet - Part 3 (http://teachers.cie.org.uk/docs/dynamic/31798.pdf)
provides notes on section 3 of the syllabus and practice problems (with answers in Computer Studies Support Booklet - Answers
(http://teachers.cie.org.uk/docs/dynamic/31801.pdf).
Outline
The concepts of sequence, selection and repetition. Input, output, totalling and counting in pseudocode and structured pseudocode for iteration (repetition) and
selection. Writing an algorithm in pseudocode and identifying and correcting errors in pseudocode.
Low-level languages, reasons for their use and their need to be translated by an assembler. High-level languages, reasons for their use and their need to be
translated by a compiler or interpreter.
Syllabus
ref
Learning
objectives
3.2.1
The concept of a
program
3.2.3
v1 2Y05
Low-level
languages
Suggested teaching activities
Learning resources
Students need to understand:
• what a computer program is
• the main requirements of a programming language to allow:
• data input and output
• manipulation of data of various types and structures
• sequence, selection, repetition and subprogram intercommunication
• the concepts of totals and counting.
LWS coursebook pp. 255–6 and 265–70
Students should perform practical exercises to:
• write algorithms in pseudocode to solve a variety of problems
• identify errors and suggest corrections in a given piece of pseudocode.
Introduce students to different types of programming languages by
considering:
Cambridge IGCSE Computer Studies (US) 0441
LWS coursebook pp. 256–7
1
Syllabus
ref
Learning
objectives
Suggested teaching activities
Learning resources
•
www.teachict.com/gcse/software/programming_languages/miniweb/p
g3.htm
Introduction to machine language
•
•
•
historical origins of computer programming in machine-specific types
of language (machine language and assembly language)
the characteristics of these languages
the need for an assembler translation program for assembly language
why they are still used for certain applications.
www.teachict.com/gcse/software/programming_languages/miniweb/p
g4.htm
Introduction to assembly language
www.teachict.com/gcse/software/programming_languages/miniweb/p
g6.htm
Introduction to translation programs for high-level
language
3.2.2
High-level
languages
Students need to identify:
• the characteristics of these languages
• the need for compiler and/or interpreter translation programs for these
languages
• why they are preferred for many applications.
Extension work:
www.mstracey.btinternet.co.uk/pictutorial/picmain.htm
Tutorial on programming a microcontroller, illustrating the
suitability of assembly language for dealing with input and
output devices
LWS coursebook pp. 257-9
www.teachict.com/gcse/software/programming_languages/miniweb/p
g5.htm
Introduction to high-level language
www.teachict.com/gcse/software/programming_languages/miniweb/p
g6.htm
Introduction to translation programs for high-level
language
Extension work:
• http://en.wikipedia.org/wiki/History_of_compiler_writing
History of compiler writing
v1 2Y05
Cambridge IGCSE Computer Studies (US) 0441
2
Syllabus
ref
Learning
objectives
Suggested teaching activities
Learning resources
•
3.2.4
Pseudocode
structures
Students do not need to be able to write program code in any particular
language for Papers 1 or 3, but should perform practical exercises to
develop recognition, understanding and writing of the following
pseudocode:
• processes:
• input (e.g. INPUT, READ, ENTER)
• output (e.g. OUTPUT, WRITE, PRINT)
• assignment (e.g. Count ← 1)
• totals (e.g. Sum ← Sum + Number)
• counting (e.g. Count ← Count + 1).
• structures:
• iteration (repetition):
• WHILE…DO…ENDWHILE:
WHILE xxx
DO
xxx
ENDWHILE
•
REPEAT…UNTIL:
REPEAT
xxx
xxx
UNTIL xxx
•
FOR…TO…NEXT:
http://en.wikipedia.org/wiki/Fortran
First high-level language to have a complete compiler
• http://en.wikipedia.org/wiki/FLOW-MATIC
The first programming language to express operations
using English-like statements
LWS coursebook pp. 260–5
www.unf.edu/~broggio/cop2221/2221pseu.htm Examples
of an approach to pseudocode that is very close to plain
English
FOR y ← xxx TO xxx
xxx
xxx
NEXT
v1 2Y05
Cambridge IGCSE Computer Studies (US) 0441
3
Syllabus
ref
Learning
objectives
3.2.4
Pseudocode
structures (cont)
Suggested teaching activities
•
Learning resources
selection:
• IF…THEN…ELSE…ENDIF:
IF xxx
THEN
xxx
ELSE
xxx
ENDIF
or nested:
IF xxx
THEN
IF xxx
THEN
xxx
ELSE
xxx
ENDIF
ELSE
IF xxx
THEN
xxx
ELSE
xxx
ENDIF
ENDIF
v1 2Y05
Cambridge IGCSE Computer Studies (US) 0441
4
Syllabus
ref
Learning
objectives
3.2.4
Pseudocode
structures (cont)
Suggested teaching activities
•
Learning resources
CASE OF…OTHERWISE…ENDCASE:
CASE y OF
n1: xxx
xxx
n2: xxx
OTHERWISE xxx or multiple
statements indented below
ENDCASE
3.2.5
v1 2Y05
User guide,
technical
documentation
This should already have been adequately covered in Unit 3: 2.2.3.
Cambridge IGCSE Computer Studies (US) 0441
5