**Zu Chongzhi (429-500)** - Or Tsu Ch'ung Chi. Gifted mathematician and astronomer who came from a family of scientists. His talent brought him to the attention of the emperor while he was still a boy, and he was sent to the finest academies in China. Wrote a treatise (which does not survive) called *Zhui Shu* (Method of Interpolation) which was said to contain the formula for determining the volume of a sphere, cubic equations and the value of ** π**. He correctly calculated the length of a year at 365¼ days and created the

*Da Ming*Calendar, which became the standard in China. He also successfully predicted the occurrence of four solar eclipses in his lifetime.