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IGCSE Computer Science 0478 — 1.3 Data Storage and Compression

Measuring data, calculating file sizes, and making files smaller.

Modules (47)

1 Bits and the binary digits 0 and 1 2 Nibble 3 Kibibyte (KiB) 4 Mebibyte (MiB) 5 Gibibyte (GiB) 6 Tebibyte (TiB) 7 Pebibyte (PiB) 8 Exbibyte (EiB) 9 The unit ladder: byte to exbibyte 10 Why storage units use 1024, not 1000 11 Converting bits to bytes and bytes to bits 12 Converting to a larger unit 13 Converting to a smaller unit 14 Converting across several units 15 Giving the answer in the unit asked 16 Image resolution 17 Colour depth 18 Number of colours from the colour depth 19 Counting the pixels in an image 20 Calculating the size of a bitmap image 21 Image file size in the unit asked 22 Sample rate and audio quality 23 Sample resolution 24 Hertz and kilohertz 25 Converting the length of a sound to seconds 26 Calculating the size of a sound file 27 Sound file size in the unit asked 28 Checking whether a file fits in the available storage 29 Compression - losing quality or saving space? 30 Why compression is needed: less storage space 31 Why compression is needed: less bandwidth 32 Why compression is needed: shorter transmission time 33 Lossy compression 34 Lossy compression permanently removes data 35 Effect of resolution and colour depth on image quality and file size 36 Effect of sample rate and resolution on accuracy and file size 37 Lossy compression of an image by reducing resolution or colour depth 38 Lossy compression of a sound by reducing sample rate or sample resolution 39 Redundancy: repeated data that can be shortened 40 Lossless compression 41 Run-length encoding: encoding text 42 Run-length encoding: decoding 43 Run-length encoding of a row of coloured pixels 44 Decoding run-length encoded image data 45 When run-length encoding makes data bigger 46 Comparing lossy and lossless compression 47 Choosing a compression format for a task

Smaller journeys, one per content description

The same modules, split up so a class can take just the content description it's working on.

Printables for this journey

Every module above has its own free printable worksheet with an answer key. These crosswords and word searches cover the same terms:

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Issues in Technology Crossword: Is AI using too much power? and more (Part 1 of 2) 10 clues · Is AI using too much power?, How does an AI actually work?, Compression - losing quality or saving space?, Why file size matters and more
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Issues in Technology Word Search: Is AI using too much power? to What is RADCAB? (All modules) 22 words to find · Is AI using too much power?, How does an AI actually work?, Compression - losing quality or saving space?, Why file size matters and more
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Years 5–6 Data & Information Crossword: Data, information and binary representation (Modules 1–10) 10 clues · Data and information, Types of data: numbers and text, Types of data: images, sound and video, Same data, different representations and more
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Years 5–6 Data & Information Word Search: Data, information and binary representation and Acquiring and manipulating data (Modules 1–20) 20 words to find · Data and information, Types of data: numbers and text, Types of data: images, sound and video, Same data, different representations and more
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Years 7–8 Data & Information Crossword: Representing data with binary and Acquiring, storing and validating data (Modules 9–45) 10 clues · 8-bit binary numbers and the range 0 to 255, Converting a larger decimal number to binary, How many values n bits can store, Looking up characters in the ASCII table and more
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Years 7–8 Data & Information Word Search: Representing data with binary to Using digital tools and conventions (Modules 9–80) 22 words to find · 8-bit binary numbers and the range 0 to 255, Converting a larger decimal number to binary, How many values n bits can store, Looking up characters in the ASCII table and more
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Years 9–10 Data & Information Crossword: Data compression (Modules 6–16) 10 clues · Redundancy: repeated data that can be shortened, Lossless compression, Lossy compression, Run-length encoding: encoding text and more
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Years 9–10 Data & Information Crossword: Data compression to Acquiring, storing and validating data (Modules 17–51) 10 clues · Choosing a compression format for a task, Content, structure and presentation of a document, Restyling one document with a different stylesheet, Why separating content, structure and presentation matters and more
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Years 9–10 Data & Information Word Search: Data compression to Data privacy and the Australian Privacy Principles (Modules 6–132) 21 words to find · Redundancy: repeated data that can be shortened, Lossless compression, Lossy compression, Run-length encoding: encoding text and more
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Crossword: 1.2 Text, Sound and Images and 1.3 Data Storage and Compression (Modules 43–58) 10 clues · Comparing ASCII and Unicode, Analogue sound waves and digital sound, Sample resolution, Effect of sample rate and resolution on accuracy and file size and more
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Crossword: 1.3 Data Storage and Compression (Modules 59–68) 10 clues · Kibibyte (KiB), Mebibyte (MiB), Gibibyte (GiB), Tebibyte (TiB) and more
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Crossword: 1.3 Data Storage and Compression (Modules 69–84) 10 clues · Converting to a smaller unit, Converting across several units, Giving the answer in the unit asked, Counting the pixels in an image and more
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Crossword: 1.3 Data Storage and Compression and 2.1 Data Transmission Types and Methods (Modules 86–109) 10 clues · Why compression is needed: less storage space, Why compression is needed: less bandwidth, Why compression is needed: shorter transmission time, Lossy compression permanently removes data and more
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Word Search: 1.1 Number Systems to 1.3 Data Storage and Compression (Modules 28–58) 20 words to find · Why two's complement is used, The sign bit worth -128, Range of 8-bit two's complement, Converting 8-bit two's complement to denary and more
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Word Search: 1.3 Data Storage and Compression (Modules 59–84) 20 words to find · Kibibyte (KiB), Mebibyte (MiB), Gibibyte (GiB), Tebibyte (TiB) and more
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Word Search: 1.3 Data Storage and Compression and 2.1 Data Transmission Types and Methods (Modules 86–120) 21 words to find · Why compression is needed: less storage space, Why compression is needed: less bandwidth, Why compression is needed: shorter transmission time, Lossy compression permanently removes data and more

Frequently Asked Questions

Are these worksheets free?

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What year level is this for?

This curriculum is aligned to the Australian Curriculum (ACARA) and Victorian Curriculum, spanning roughly Years 3 to 10 — from first sequencing and variables through to object-oriented programming and advanced data structures. Start wherever matches your class's current level; each module builds on the last.

Can I print them?

Yes — every module has a one-click Print Worksheet button that generates a printable page with the practice questions and a full answer key.

Is this aligned to a curriculum?

Yes — the module sequence is mapped to the Australian Curriculum (ACARA) and Victorian Curriculum, and a class's progress is reported back against those curriculum bands (e.g. ACARA Years 5–6 sequencing and iteration, Years 7–8 functions and data structures), not just a generic difficulty scale.

Can students use this without a teacher?

Yes — students can start any module and practice directly, no class or account required. Joining a teacher's class with a class code adds progress tracking, class badges, and live Sprints, but isn't needed to work through the worksheets or modules solo.

Do I need to know IGCSE Computer Science Paper 1 myself to teach this?

No — every module comes with a full worked answer key, and Cloodit tracks who's stuck automatically, so you don't need to solve each exercise yourself before assigning it or be able to debug a student's work line by line.

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