Working in hex or binary can feel strange and confusing compared with the base 10 number system used in our everyday world. It's not rocket science, but it requires adjusting how one thinks about ...

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.

Binary arithmetic, the basis of all virtually digital computation today, is usually said to have been invented at the start of the eighteenth century by the German mathematician Gottfried Leibniz ...

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.