The Incas used colorful knotted cords called Quipu to record numbers and archives such as census data, tax obligations, and storehouse records. They had up to a thousand unique strands. – WTF Fun Facts
Source: https://en.wikipedia.org/wiki/Quipu
WTF Fun Fact – Inca Quipu
I think the Incas had way too much free time on their hands for a system that complex. Get an alphabet already. 😉