Key Stage 3 lessons for the terrified
BINARY
TEACHER OVERVIEW
Binary is a way of counting. It is used in computers because it is easier to get them to work in either
one of two states - on or off, to have power turned off or power turned on. Therefore everything
that computers do is processed as 0s or 1s.
This is quite a difficult concept to understand – ‘all computers work only in 0s and 1s’. All presses of
the keyboard, all pieces of software, even the letters in this word processed document has to be
turned into 0s and 1s, but this is fundamental to understanding computers and their workings.
It is quite an intellectual exercise to get learners to think about how electrical circuits can be used to
add numbers together and the relation and the relation to how real computers work and there has
to be careful progression to get to a meaningful end.
It is however my experience that learners like doing this ‘stuff’.
In their prior learning they have met the concept on binary in Mathematics.
Process:
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Converting numbers from ordinary numbers to binary and vice versa
Playing a conversion game
Adding binary numbers together
Looking at how quick computers are
RESOURCES
The resources are held in this folder: https://slp.somerset.org.uk/sites/edtech/Secondary Computing/Binary
These include:
Binary Presentation
Binary Worksheet
Large Binary Cards
Small Binary Cards
Teacher resources
PowerPoint that describes can be used throughout the lesson
Worksheet for converting numbers and with some simple
addition problems
A4 Cards with binary numbers
Small binary cards for individual work
More links to other resources
Key Stage 3 lessons for the terrified
Load the PowerPoint presentation binary
Get them to say what things make them brainier than a
computer – record these. (slide 2)
You should push them into ideas on
creativity and ability to do many different
things.
Once you have completed this ask if they
think they can do sums quicker than a
computer.
Then ask the question how does a computer count
(slide 3)
The columns within binary are powers of 2
32
You might like to show them the James May clip from
YouTube
http://www.youtube.com/watch?v=kcTwu6TFZ08.
Selecting the section from 2.04 to 4.00 mins might be
less confusing at this point
Select five members of the class and give them each
one the large binary cards
16
8
4
2
1
With number made up of turning these
columns off or on.
The exercise with the cards makes this a
physical activity which the learners seem
to like
Show them how numbers can be represented by
turning cards on or off – 0 or 1.
Give each learner a pack of the small binary cards.
You may have to support the less able.
Get every child/pair to convert numbers from base ten
to binary and back again. They can record their results
on the worksheet. Use slide 4 to show the numbers you
want calculated binary worksheet.
There are no reasons that learners have to
be able to do this work – just understand
the concept.
They can work in pairs.
Get the learners to play the Tetris like game at:
http://forums.cisco.com/CertCom/game/binary_game_
page.htm (Slide 5).
Now ask the question – How can I add binary numbers
(Slide 6).
It is such an easy concept for us to add
simple numbers but for a computer it is
quite a difficult action. They cannot make
decisions. Think of the understanding and
decisions you make when you add
together to numbers such 6 and 7.
Key Stage 3 lessons for the terrified
Lead the group through how binary numbers can be
added together (Slides 7, 8 and 9). You might need to
do several other examples.
Get them to have a go at the sums on the binary
worksheet.
The key to the computers power is the fact that they
can do repeated calculation quickly and accurately.
These next slides which are based on approximate
calculations show how fast a computer is.
The key to a computers power is its speed (Slides 11, 12
and 13).
Finally show them slide 14
They are all cleverer than a computer because they can
do sums that do not have to use binary.
These figures are approximate but give an
idea based on class size about how fast
computers can work.