Measure data in bits, bytes and binary prefixes
Convert between the syllabus storage units using eight bits per byte and 1024 for each binary prefix step.
This sequence follows Cambridge IGCSE Computer Science 0478, 2026–2028 syllabus Version 6. It covers subject content sections 1.1–1.3 only. The separately published 2029–2031 syllabus is not mapped here. Practice is original, self-checked and does not award an official Cambridge grade. Full timed papers and human subject-teacher review remain outstanding.
Before you begin
- No programming language is required. Be comfortable with place value and multiplication; each lesson introduces the computer-science notation it uses.
Work on paper. Try each question before revealing help, and explain why your method works.
Quick readiness check
How many bits are in one byte?
What you will learn
- Define a bit, nibble and byte
- Convert through KiB, MiB, GiB, TiB, PiB and EiB
- Use 1024 rather than 1000 for syllabus binary-unit calculations
Small units build upward
A bit is one binary digit. A nibble is four bits, and a byte is eight bits. One kibibyte (KiB) is 1024 bytes; each next binary prefix is 1024 of the previous unit: MiB, GiB, TiB, PiB and EiB.
Apply and check the rule
Always preserve the unit while converting. Moving to a larger unit divides by 1024; moving to a smaller unit multiplies by 1024. The syllabus requires 1024 rather than 1000 for these calculations.
Pause and explain
How many KiB are in 1 MiB for this syllabus?
Worked example
Convert 3 MiB to KiB.
Show the worked solution
- 1 MiB=1024 KiB.
- Multiply 3 by 1024.
- 3×1024=3072.
Answer 3072 KiB
Try a topic test
Choose Easy, Normal or Difficult. Save your answers and open worked review after finishing.
Test this topic →From guided practice to a new situation
Write your answer and reasoning first. Use a hint only if you are stuck. The model solution is for self-checking; your written work is not automatically marked.
Convert 5 KiB to bytes.
Give me a hint
Multiply by 1024.
Compare my reasoning
- 1 KiB=1024 bytes.
- 5×1024=5120 bytes.
5120 bytes
Look for these in your work
- 1024 used
- Unit changed to bytes
- Result correct
Convert 2 GiB to MiB.
Give me a hint
One GiB contains 1024 MiB.
Compare my reasoning
- 2×1024=2048.
- Keep the target unit MiB.
2048 MiB
Look for these in your work
- Correct factor
- Correct target unit
A backup device has 3 TiB of capacity. How many MiB is that? Show the unit steps.
Give me a hint
Move from TiB to GiB to MiB; multiply by 1024 at each step.
Compare my reasoning
- 3 TiB×1024=3072 GiB.
- 3072 GiB×1024=3,145,728 MiB.
- Two prefix steps mean multiplying by 1024².
3,145,728 MiB
Look for these in your work
- Both prefix steps shown
- 1024 used twice
- Final unit MiB
Common mistakes
- Using 1000 instead of 1024
- Changing the number without changing its unit
What can you explain now?
How many bytes are in 2 KiB?
Compare with the explanation
2048 bytes
A kibibyte contains 1024 bytes, so 2×1024=2048 bytes.
After trying it yourself, choose your next review. This is your self-assessment.
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Make it stick
When converting from a larger binary unit to a smaller one, do you multiply or divide by 1024?
If you needed the solution, close it and solve the problem again from a blank page. A correct answer is stronger when you can explain the reason for each step.