Isolated Polynesian culture combined binary and decimal arithmetic

Nature : Binary arithmetic, the basis of nearly all modern computing, greatly simplifies basic math because it involves learning just a few rules instead of memorizing lots of sums and multiplication tables. However, one of the difficulties of working with binary is that large numbers require lots of digits. Andrea Bender and Sieghard Beller of the University of Bergen in Norway have found evidence of a historical number system that combined the benefits of binary and decimal arithmetic. They were studying records from visitors to the island of Mangareva in French Polynesia and found descriptions of a now defunct counting system that used words for the numbers 1 through 10 and then for 10 multiplied by powers of 2 (for example, 20 = 10 × 2¹, 40 = 10 × 2², and so on). Bender and Beller showed that the system relies on the simple rules of a true binary system, but avoids the long strings of digits that are normally required. They believe that the system developed to handle the accounting for measuring trade between tribes and tribute to tribal chieftains.