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Glossary
Look up any term from this course. Each entry links back to the lesson that taught it.
| Term | Definition | Lesson |
|---|---|---|
| Base (radix) | The number of different digits a number system uses, which is also the multiplier between one place and the next. | Place Value and Number Bases |
| Binary | Base 2. Uses the digits 0 and 1. Place values 1, 2, 4, 8, 16 … | Place Value and Number Bases |
| Bit | A binary digit — the smallest unit of data, with a value of 0 or 1. | Why Computers Use Binary |
| Byte | A group of 8 bits, the basic unit used to measure memory and storage. | Why Computers Use Binary |
| Decimal (denary) | Base 10 — the everyday number system, using the digits 0–9. | Place Value and Number Bases |
| Hex colour code | A colour written as #RRGGBB: two hex digits (one byte) each for red, green and blue. | Number Systems in Real Life |
| Hexadecimal | Base 16. Uses 0–9 and A–F (A = 10 … F = 15). One hex digit equals four bits. | Place Value and Number Bases |
| Leading zero | A zero added to the left of a number. It does not change the value and is used to complete a group of 3 or 4 bits. | Binary and Octal |
| Nibble | Four bits — half a byte, and exactly one hexadecimal digit. | Why Computers Use Binary |
| Octal | Base 8. Uses the digits 0–7. One octal digit equals three bits. | Place Value and Number Bases |
| Place value | The value a digit has because of its position in a number. Each position is worth the base raised to a power, starting from 0 on the right. | Place Value and Number Bases |
| Repeated division | Method for converting decimal to another base: divide by the base until the quotient is 0, then read the remainders from bottom to top. | Decimal to Binary, Octal and Hexadecimal |
More lessons in Number Systems · Previous: Course Exam