Zhu Shijie (Chinese: 朱世杰, Hanqing 字 漢卿, 號 松 庭) (mid-1270? -1330?) also known as Chu Shih-Chieh was one of the most eminent Chinese mathematicians.
Little is known about his life, although two mathematical works of his authorship are preserved. His introduction to mathematical studies (算 學 啟蒙, Suanxue qimeng) of the year 1299 is an elementary book of mathematics. Zhu included 260 problems that explain operations of arithmetic and algebra. The book also shows how to measure two-dimensional shapes and three-dimensional bodies. The original in Chinese was very influential in the development of mathematics in Japan and Korea. The original book in Chinese had been lost until a translation was made from a copy in Korean in 1839.
The second conserved book of Zhu, titled The Precious Mirror of the Four Elements (四 元 玉 鑒, Siyuan yujian) of the year 1303, is his most important work. With this book Zhu took Chinese algebra to the highest level. It includes an introduction to his method of the four elements, which is used to talk about four indeterminate quantities in an algebraic equation. Zhu also clarified how to find square roots and developed the knowledge of series and progressions. The preface to the book explains how Zhu traveled through China teaching mathematics for 20 years.
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