Zu Chongzhi, a knowledgeable and far-sighted man, was born in 429 AD and died in 500 AD. His ancestral home is Kuai County, Fanyang, Hebei Province (now Laishui County, Hebei Province). His family, starting from his grandfather's uncle, mainly studies astronomy, calendar and mathematics. Zu Chongzhi has read many books on astronomy and mathematics since he was a child. He studied hard, practiced hard, personally observed the astronomical phenomena and made calculations. Finally, he became an outstanding mathematician and astronomer in ancient China. Zu Ti (266-32 1 year), a native of Que County, Fanyang County (now Laishui County, Hebei Province), was a famous patriotic general in the Eastern Jin Dynasty.