Binary

A way to represent numbers using only 0 and 1.

Binary is a representation system. It uses place value like denary, but each place is worth twice as much as the one before.

Tiny example

Read 1011

In binary, 1011 means 8 + 0 + 2 + 1.

So 1011 in binary represents 11 in ordinary base ten.

Why it matters

Binary connects pattern, representation and computation. It is one of the simplest examples of how changing notation changes what a machine can do.

Reading binary as if it were base ten.
Forgetting the place values double each time.
Thinking binary is only a computing trick rather than a mathematical representation.

place valuepowerscomputer science

Encode, decode and attack simple ciphers using shifts, keys and letter frequencies.