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.

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.

The binary system can represent any number using a string of 1s and 0s. Though it is used by computers today, it was first described by the 17th century mathematician Gottfried Leibniz.

Leibniz wrote his system in an article called “Explication de l’Arithmétique Binaire” or “Explanation of the Binary Arithmetic” in 1703. In the article, he showed how the use of zeroes ...