The document provides an overview of the historical development of methods for calculating pi. It discusses ancient approximations of pi from cultures like Egypt, Babylon, and India. It describes how Archimedes developed the first mathematical analysis and algorithm to approximate pi by calculating the circumference of polygons with increasingly more sides. Later developments include Machin's fast-converging formula using arctangents and Euler's new method for calculating arctangent values. The document traces the history of pi calculations through various mathematicians and cultures over thousands of years.