GCSE Computer Science: Data Representation Revision

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What is the denary value of binary 10110?

Data Representation is a core part of GCSE Computer Science. Revise the key concepts and common mistakes below, then lock them in with the free games.

Key concepts

BinaryBase-2 representation using only 0s and 1s.

HexadecimalBase-16, a shorthand for binary (0–9, A–F).

Bits & bytesA bit is one binary digit; 8 bits make a byte.

Character encodingASCII and Unicode represent text as binary codes.

Image representationImages stored as pixels with a colour depth.

Sound representationSound sampled at a rate and bit depth to store digitally.

Logic gatesAND, OR and NOT process binary inputs.

Truth tablesShow every output for all input combinations.

Boolean algebraRules for manipulating logic expressions.

AND gateOutput is true only when all inputs are true.

OR gateOutput is true when at least one input is true.

NOT gateInverts a single input (1→0, 0→1).

ExpressionA combination of variables and Boolean ops.

PrecedenceOrder: NOT first, then AND, then OR.

What your exam board covers

Where Data Representation sits in each exam board's specification. Tap a board to see what it lists.

AQAFundamentals of data representationSpec 8525

Number bases and binary
Units of information
Binary arithmetic and hexadecimal
Representing characters, images and sound
Data compression

Source: AQA GCSE Computer Science (8525) specification — Subject content, accessed 23 June 2026.

EdexcelData representationSpec 1CP2

Part of: Data

Source: Pearson Edexcel GCSE Computer Science (1CP2) specification, accessed 23 June 2026.

Cambridge IGCSEData representationSpec 0478

Number systems
Text, sound and images
Data storage and compression

Source: Cambridge IGCSE Computer Science (0478) syllabus, accessed 23 June 2026.

Learn Data Representation step by step

Free interactive mini-lessons: short screens, worked examples and quick checks. Pick your exam board:

Other boards:OCR

Common mistakes to avoid

Questions where students often pick the tempting wrong answer — make sure you know the right one:

What is the denary value of binary 10110?✗ 10110 (treating it as a denary number). ✓ 22 (16 + 4 + 2).

What happens when 11111111 + 1 is computed in an 8-bit register?✗ It just becomes 100000000 normally. ✓ Overflow - the result requires 9 bits but only 8 are available.

How do computers store all data?✗ In ordinary decimal numbers. ✓ As binary — 0s and 1s.

What affects the file size of an image?✗ Only the size of the screen showing it. ✓ Resolution (number of pixels) and colour depth.

Does the binary number 10 mean ten?✗ Yes - 10 is ten no matter what base it is written in. ✓ No - in binary, 10 means one two and zero units, which is the denary value two; the same symbols mean different values in different bases.

Practise Data Representation — free games

Test yourself with these quick revision games for this topic:

▶ Two Truths, One Lie ▶ Reveal Race ▶ Connections Grid ▶ Falling Words ▶ Word Web

See all 22 games in the Revision Arcade →

Data Representation

Key concepts

What your exam board covers

Common mistakes to avoid

Practise Data Representation — free games

More GCSE Computer Science topics