Question

How did the inca make such precise calculations in astronomy, architectal engineering and mathmatics?

Answer 1

They recorded numbers using the knots on a string called a quipu.

Answer 2

The Inca were able to make very precise calculations in astronomy, engineering and mathematics due to their use of quipu. A quipu is a recoding device made out of strings and used by a number of cultures in the Andean area. It consists of a number of strings that are tied into knots in a particular symbolic pattern. Quipu were also used to collect data, maintain records, collect census records and other types of organizational tasks.