2. In the 3rd century BC, the Greek mathematician Archimedes was the first person to scientifically calculate π, which is roughly equal to 3. 14.
3. Zu Chongzhi (429-500) was named Wen Yuan. Jiankang (now Nanjing) was an outstanding mathematician and astronomer in the Southern and Northern Dynasties. Zu Chongzhi studied natural science all his life, mainly contributing to mathematics, astronomical calendar and mechanical manufacturing. On the basis of exploring the accurate method of pi pioneered by Liu Hui, he first calculated the "pi" to the seventh place after the decimal point, that is, between 3. 14 15926 and 3. 14 15927. His "ancestral rate" has made great contributions to mathematical research. It was not until the 6th century A.D./KLOC-that the Arab mathematician Al Cassie broke this record.
4. The Daming Calendar written by him was the most scientific and progressive calendar at that time, which provided a correct method for astronomical research in later generations. His main works are In the Frontier, Composition, Explaining Words, Li Yi and so on.