The Incas had a system of accounting that relied on the quipu. Cords of various colours were attached to a main cord with knots. The number and position of knots as well as the colour of each cord ...

For more than a millennium, many Andean peoples used an object called a "khipu" (also spelled "quipu" and pronounced "key-poo") to record and communicate information. Khipus were made with cords ...