Incan numerical recordkeeping system may have been widely used
Inca bureaucrats recorded all the goings-on in their bustling empire using knotted cords called khipu, where the position and order of the knots represented numbers. They relied on the khipu system to track people, taxes, produce, livestock, and products like woven cloth and beer. Because khipu were so vital to the Inca government, and because the khipu itself is such a sophisticated way of recording numbers, colonial writers decided that these tools must be the exclusive knowledge of a very sp