01001000 01100101 01101100 01101100 01101111 00100001. Those ones and zeros might not look like anything to you, but in binary code the numbers are actually saying “Hello!”. Any code that uses just ...

The first versions of ASCII used 7-bit codes, which meant they could attach a character to every binary number between 0000000 and 1111111, which is 0 to 128 in decimal.

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.