Size Matters (Binary Edition)
How big is a file, really? Climb the binary units ladder from bit to tebibyte, learn why this board counts in 1024s, and take on real storage-capacity calculations.
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How big is that file? 💾
Everything a computer stores is made of **bits** - single binary digits, each a 0 or a 1. Group them up and you can measure the size of a photo, a song or a whole hard drive. This module climbs the units ladder from a single bit to a **tebibyte**, and shows why this exam board counts storage in steps of **1024**, not 1000.
The smallest units 🔑
Start at the bottom of the ladder:
Climb the units ladder 🪜
An interactive activity.
The 1024 rule ⚠️
This board uses **IEC binary prefixes**, so each step up the ladder multiplies by **1024**, which is 2^10 - NOT 1000. 1 KiB = 1024 bytes, 1 MiB = 1024 KiB, 1 GiB = 1024 MiB, and 1 TiB = 1024 GiB. If you have also met the decimal prefixes (kB = 1000 bytes), you must switch conventions here, or every storage calculation will drift further out with each unit step. Always show the power-of-two working.
Bytes in a kibibyte 🔢
An interactive activity.
Which statement is correct? ✅
Under the binary (IEC) prefixes this board uses, which of these is TRUE?
- 1 MiB = 1024 KiB
- 1 MiB = 1000 KiB
- 1 MiB = 1024 bytes
- 1 KiB = 1024 bits
Convert the file size ➗
An interactive activity.
Two prefix systems ⚖️
The same letters can mean different amounts. Knowing which system you are in matters.
Match each unit to its size 🔗
- Nibble
- Byte
- Kibibyte (KiB)
- Mebibyte (MiB)
- 4 bits
- 8 bits
- 1024 bytes
- 1024 kibibytes
Storage in words 🧩
A single binary digit is a _____. Eight of them make a _____. This board measures storage with _____ prefixes, so 1 kibibyte is _____ bytes. Because a value is stored in a fixed number of bits, there is a limit to the _____ whole number it can hold.
Limits of binary 🎯
A value is always stored in a fixed number of bits. Select the TWO true statements about this limit.
- A fixed number of bits limits the largest whole number you can store
- Storing fractions in a fixed number of bits can lose precision
- Adding more bits always makes stored numbers less accurate
- Eight bits can represent any whole number exactly
Spot the true statements 🖍️
An interactive activity.
The storage showdown 🧭
An interactive activity.
Why 1024, not 1000? ✍️
An interactive activity.