Data Representation and Number Systems

What the resources cover

The unit starts with number systems. You will find quizzes and decks on binary, denary and hexadecimal, plus conversion practice such as Binary/Denary Conversion and Adding Binary. The mind map on hexadecimal explains why hex is used and how to convert between hex and binary. Two flashcard decks, Hex 1: Hex & Denary and Hex 2: Hex & Binary, break conversions into steps, such as splitting a byte into two nibbles.

Beyond numbers, the maps cover units of data (bit, nibble, byte), bitmap images made of pixels, sound, and file formats. Others look at compression, lossy and lossless, and at error detection with parity bits. There are also resources on ASCII and Unicode.

Where to start

1. Read the mind map GCSE AQA Computer Science - Data Representation for an overview of the whole topic.
2. Work through the units of data in the mind map Bits and Bytes.
3. Practise conversions with the quiz Binary and Denary conversions, then move on to hexadecimal.
4. Learn the steps for hex with the two Hex flashcard decks.
5. Move on to images, sound and compression once the number work feels steady.

Using quizzes and maps together

Read a map first, then test yourself. If a quiz exposes a gap, go back to the matching map or deck and look at that branch again. The quiz GCSE CS Data Quiz (Binary shifts) is a good check on logical shifts. The File type extensions quiz checks whether you know a JPEG from an MP3 or an AVI.

Where this unit sits

This unit belongs to the Computer Systems strand of Computing and ICT. Most of what is listed is aimed at school students, with names like GCSE Computer Science, IGCSE ICT and A-level Computing appearing across the resources. Teachers can use the slide sets, notes and quizzes as ready-made starting points.

Choose one topic from the list above, open its map and see how much you can recall before trying the quiz.