9618 · 1.1
Data Representation
Computers only understand 'on' and 'off', represented by 1s and 0s (binary). We use clever systems to turn these simple signals into numbers, text, and all the complex data we use every day.
Need to know
What you need to know
- Each position in a binary number represents a power of 2 (e.g., ..., 128, 64, 32, 16, 8, 4, 2, 1).
- Hexadecimal is a compact notation for binary. Each hexadecimal digit corresponds to a unique 4-bit binary sequence (a nibble).
- For example, the hexadecimal digit `B` is equivalent to the denary number 11, which is `1011` in binary.
- A single byte (8 bits) can be represented by exactly two hexadecimal digits (e.g., `11111111`₂ = `FF`₁₆ = 255₁₀).
Explanation
The Language of Computers
- Denary ↔ binary using place value (powers of 2).
- Hexadecimal: one digit = 4 bits — compact notation.
- Characters stored as numeric codes (ASCII / Unicode).
- Two's complement represents signed integers.