(1) Han Dynasty: Nine Chapters of Arithmetic was written in the Eastern Han Dynasty. It introduces many arithmetic propositions and their solutions in nine chapters. It was the most advanced applied mathematics in the world at that time, and its appearance marked the formation of a complete system of ancient mathematics in China.

(2) Northern and Southern Dynasties: ① Liu Hui, a mathematician in Wei and Jin Dynasties, put forward a correct method to calculate pi by using limit theory. ② Zu Chongzhi in the Southern Dynasties accurately calculated pi between 3.1415926-3.1415927, which was nearly a thousand years earlier than foreign countries. His monograph seal script has made outstanding contributions to the development of mathematics.