Remember that the Incas had no written records and so the quipu played a major role in the administration of the Inca empire since it allowed numerical information to be kept. ... The quipu consists of strings which were knotted to represent numbers.

Did the Inca have writing?

The Incas never developed a written language. However, their system of record keeping called Quipu is unique in human history. Inca recorded accounts with knotted string. Quipu means knot in Quechua, the language of the Incas.

What did the Incas keep records on?

A quipu usually consisted of cotton or camelid fiber strings. The Inca people used them for collecting data and keeping records, monitoring tax obligations, properly collecting census records, calendrical information, and for military organization.