Zu Chongzhi (429 - 500) lived in the period of Song and Qi of Southern dynasties. He devoted himself to study in his youth, being especially fond of mathematics. He also liked ancient astronomical research.

Zu Chongzhi greatest achievements lay in maths. He calculated a more precise ratio of the circumference of a circle. Pi is the ratio between the diameter and circumference of the circle. Ancient Chinese understood this concept very early, but not too accurately. Zu Chongzhi summed up the experience and decided to use the way of "Cut Circle" pioneered by Liu Hui, who lived in the period of "Three Kingdoms", to seek pi. However, the computation tools at that time were bamboo sticks. For the nine-digit arithmetic, 130 times of computation were needed, which was prone to error. Zu Chongzhi repeated each count at least twice. until a few calculations got the same results. After working hard on the calculation, he finally reached the ratio of the curcumference of a circle to its diameter at between 3.1415926 and 3.1415927.

Zu Chongzhi was the world's first scientist operator to put pi seven digits after the decimal point. And it was not until the 15th century that an Arab mathematician named Al-Kashi and a 16th century French mathematician Viete surpassed him by projection it to 16 digits after the decimal point. In addition, Zu Chongzhi compiled his major achievements in mathematics into a book called Zhuishu, which became the main textbook on mathematics in China during Tang Dynasty.