Zhu Shijie

(flourished 1300, China) Chinese mathematician who stood at the pinnacle of traditional Chinese mathematics. Zhu is known for having unified the southern and northern Chinese mathematical traditions. His fame rests on two publications, Suanxue qimeng (1299; “Introduction to Mathematical Science”) and Siyuan yujian (1303; “Precious Mirror of Four Elements”). The former is an introductory mathematics textbook; following the southern Chinese tradition, it presents many rules and problems in the form of verses to facilitate their memorization. It played a central role in the development of the wasan (“Japanese calculation”) tradition. “Precious Mirror” corresponds to the final stage in the generalization of the northern Chinese technique of tian yuan (“method of the celestial unknown”), a kind of algebraic computation performed with counting rods to solve problems.