Binary and number bases

We count in base 10 because we have ten fingers. Computers use base 2 (binary), with just 0 and 1. Hexadecimal (base 16) is a short way of writing binary.

Key facts

• Binary column values: …, 16, 8, 4, 2, 1.
• Hexadecimal digits: 0–9 then A (10) to F (15).
• To convert to a base: divide repeatedly and read the remainders upwards.
• One hex digit = four binary digits.

Worked examples