But to represent larger numbers, binary needs a lot more digits. Take this number in binary 10110111. ... While this is a pretty big range of numbers, it's not enough for many tasks.

When the numbers are within the range of 10 to 19, the binary representation varies between four and five bits, such as 1010 to 10011. The BCD representation uses eight bits, such as 0001 0000 to ...

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.

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.

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.

But, for medium size numbers, the system switches over to binary. The Mangarevans had special words for 10, 20, 40, and 80 — the first few powers of two, multiplied by ten.