Zu Xuan, whose real name is Jing Shuo, is the son of Zu Chongzhi, a mathematician and scientist in the Southern Dynasties. After Zu Chongzhi's death, he wrote to Liang Chaotian three years (AD 504), eight years and nine years, suggesting that Da Liming, who adopted his father, finally realized his father's last wish. Zu Xuan's main job is to repair and edit his father's mathematical work "Composition". On the basis of practice, he put forward the famous ancestral principle: "If the potential is the same, the accumulation cannot be tolerated". Here, "force" and "potential" refer to the cross-sectional area and height of geometric figures respectively. Translating into modern Chinese is axiom 6 on page 94 of the textbook. He developed his father's research results by using this principle and the open circle technology he created, and skillfully proved that the volume formula of the ball is where D is the diameter of the ball. He found that this formula was at least 65,438 years earlier than the Italian mathematician Bonaventura Envalieri (A.D. 1589- 16438). There are many other scientific discoveries made by Zu Xuan, such as affirming that Polaris is not really at the north celestial pole, but is off by more than one degree. Calculating these results is inseparable from his rich mathematical knowledge.