Our usual system is called decimal, or base 10, and counts in chunks of 10. The binary system, also known as base two, counts in chunks of two. As an example, let's count this collection of asterisks: ...

Binary coding is a system of counting that boils down to two digits—one (1) and zero (0) that represent ON and OFF, respectively. The binary system is the core of all binary codes.

Unlike our everyday counting system that uses tens, binary uses just two numbers, 0 and 1. Learn more with BBC Bitesize. Suitable for KS3 students.

As computers became more sophisticated, binary code became the most used language. Leibniz’s development of the code set the foundation to bring forth the Digital Age almost 300 years before.

But for numbers 20 through 80, they used a binary system, with separate, one-word terms for 20, 40 and 80. For really large numbers, they used powers of 10 up to at least 10 million.