Qin Jiushao, an official and mathematician in the Southern Song Dynasty, is also known as the Four Masters of Mathematics in the Song and Yuan Dynasties with Ye Li, Yang Hui and Zhu Shijie. Han nationality, claiming to be from Lujun (now Qufu, Shandong) and Anyue, Zhou Pu (now Sichuan). He studies astrology, rhythm, arithmetic, poetry, bows and arrows and creation. He was a magistrate in Qiongzhou, a farmer and was later demoted. He died in Meizhou, where he wrote "Nine Chapters", in which the great derivative, the triclinic quadrature and Qin's algorithm are important contributions of world significance.

Qin was born in the first year of Jiading in the Southern Song Dynasty (1208). In the second year (126 1), he died in Meizhou (now Meixian County, Guangdong Province). China ancient mathematician. Shao Ding of Qin and Song Dynasties was admitted as a scholar for four years (123 1). He worked as an official in Hubei, Anhui, Jiangsu, Zhejiang and other places, and was demoted to Meizhou (now Meixian County, Guangdong Province) around 126 1, and soon died. In his spare time, he devoted himself to mathematics. And widely collect calendar, mathematics, astrology, temperament, architecture and other materials for analysis and research. During Song Chun's four to seven years (1244- 1247), while mourning for his mother, he edited and sorted out the long-term accumulated mathematical knowledge and research results, wrote the famous book "Nine Chapters of Mathematics" and created "Seeking a Skill". This was not only in the leading position in the world at that time, but also played an important role in modern mathematics and modern electronic calculation design, and was called "China's remainder theorem". His theory of "pros and cons" is called "Qin scheme". Now, almost all countries in the world have been exposed to the theorems, laws and problem-solving principles he discovered in mathematics courses from primary schools to middle schools to universities. Qin's achievements in mathematics were more than 800 years earlier than those of British mathematicians.

Qin is very clever, paying attention everywhere and learning tirelessly. When my father was a doctor and minister of industry, it was the time for him to study hard and accumulate knowledge. The Ministry of Industry is in charge of construction, the Secretariat is in charge of books, and its subordinate institutions are Taishi Bureau. Therefore, he had the opportunity to read a lot of classics, visit experts in astronomical calendar and architecture, ask questions about astronomical calendar and civil engineering, and even get to know the construction situation in depth. He studied mathematics from the "hermit" and lovers' poems from the famous poet Li Liu, and reached a high level. Through this stage of study, Qin became an erudite young scholar. At that time, people said that he was "extremely intelligent in sex. He studied astrology, temperament, arithmetic and even creation."

The book Shu Shu Jiu Zhang consists of nine chapters and nine categories, 18 volumes, and each category has 9 questions * * * 8 1 calculation questions. The writing style of this book is mostly composed of four parts: question, answer, skill and scolding: "question" is to ask questions from real life; "Answer" means giving an answer; "Shu Yue" is to explain the principle and steps of solving problems; Cao Yue gives a detailed process of solving problems. In addition, there are tributes under each category, which are concise and concise, and are used to describe the main contents of this kind of calculation problems, their relationship with the national economy and people's livelihood and their solutions. This book is in the form of problem sets, without mathematical classification. Inscriptions not only talk about mathematics, but also involve natural phenomena and social life, which has become an important reference for understanding social politics and economic life at that time. There are many innovations in mathematical research in Shu Shu Jiu Zhang. China's counting method and its formula are completely preserved here; Natural numbers, fractions, decimals and negative numbers are all discussed in special articles, and decimals are used to express the approximation of irrational roots for the first time.

Liang Zongju, a Chinese historian of mathematics, commented: "Qin's Book of Nine Chapters (1247) is an epoch-making masterpiece with rich content and superb level. In particular, the method of large derivative (the only solution of China's infinitive equation) and the numerical solution of higher algebraic equations had a lofty position in the history of world mathematics at that time. At that time, the long academic night in Europe was not over yet, but the creation of China people shone like the rising sun in the East. "