Years 3–6 · Week 4 of 12
Bits and Ordinary Computers
Learning goals
By the end, you can…
- Identify 0 and 1 as the two values of a bit.
- Use a row of bits to encode a small black-and-white picture.
- Explain that groups of bits can represent different kinds of information.
- Explain why a household switch is only an analogy for a physical bit.
What you already know
Connect to a familiar idea
You already use devices that store words, pictures and sounds. Inside, those devices represent information using controlled physical states.
- Recognise repeating patterns.
- Follow a simple row-and-column grid.
Opening story
Start with something familiar
A tiny black-and-white picture can be sent as instructions: colour this square white for 0 and black for 1. A computer can rebuild the picture when both sides agree on the code.
Plain-English explanation
Build the idea carefully
Meet the bit
Ordinary computers store and process information using bits. A bit has one of two values, written 0 or 1.
Build information from bits
Groups of bits can represent numbers, letters, colours, sounds and instructions when a code is agreed. Real bits can be built with electrical, magnetic, optical or other physical states; they are not literally household switches.
Try the model
Switch, encode and decode
Toggle the bit switches to draw a five-by-five picture, then copy its zeroes and ones into the decoder.
Ready. Adjust a control, then run the model.
What this model shows: This board models logical bit values. A real device uses physical hardware.
Text alternative for this interactive
Colour a printed five-by-five grid from the supplied zero-and-one code.
Expected observation: Changing one bit changes one coded square, and the same bit pattern rebuilds the same picture when the code rule stays fixed.
Guided activity
Send a secret pixel picture
- Draw a simple picture using only white and filled squares.
- Write its squares as zeroes and ones, row by row.
- Ask a partner to decode the bits without seeing the first picture.
Evidence to collect: The partner's decoded grid matches the original when the bit order and coding rule are followed.
Glossary
Words to know
- bit
- A unit of ordinary digital information with value 0 or 1.
- binary
- A system that uses two symbols or values.
- encode
- Turn information into an agreed code.
- decode
- Use the agreed rule to recover the information.
Short recap
Keep these ideas
- A classical bit has value 0 or 1.
- A bit pattern gains meaning from an agreed code.
- Physical bits have many designs; the switch picture is only an analogy.
Knowledge check
4 clear questions
Choose an answer for immediate feedback. You may retry, and your best submitted score is kept.
Explore More Optional extension for Years 5–6
Binary place values double as you move left: 1, 2, 4, 8 and so on. That lets a short bit string represent an ordinary number.
Try this
Use four cards worth 8, 4, 2 and 1. Turn cards on to encode the numbers from 0 to 15.
Adult support Teacher and parent notes
Discuss
- Separate a logical value from the hardware that stores it.
- Ask how changing the agreed code could change the meaning of the same bits.
- Use black and white patterns if colour perception or printing is a barrier.
Answer guidance
A successful explanation mentions two values, a consistent order and a shared encoding rule.
Offline activity
Pair learners as sender and decoder with paper grids. Include row numbers so bit order remains clear.
Safety
Do not open computers or electrical devices. The activity needs only paper or the on-screen board.
Sources and further reading
Checked references for this lesson
These sources support the lesson’s main scientific claims. Links open on the source organisation’s site.
- Classical information IBM Quantum Learning · official learning module · checked 2026-08-02
- Basics of Quantum Information IBM Quantum Learning · official course · checked 2026-08-02
- Quantum information science National Institute of Standards and Technology · government explainer · checked 2026-08-02
Content review: Reviewed on 2026-08-02.