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 ...

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.

They find that the former Mangarevans combined base-10 representation with a binary system. They had number words for 1 to 10, and then for 10 multiplied by several powers of 2.