During the four to seven years (A.D. 1244- 1247), during the three years of his mother's death in Huzhou, Qin edited and sorted out the long-term accumulated mathematical knowledge and research results, and wrote the world-famous mathematical masterpiece Nine Chapters. This book was not published after it was written. The manuscript is almost lost and the title is not exact.

After the Song and Yuan Dynasties, when the Ming Dynasty was founded, this book was left out in the cold. It was not until the Yongle period of the Ming Dynasty that Jie Jin compiled the Yongle Grand Ceremony that the title was recorded as Nine Chapters of Mathematics. After more than one hundred years, it was copied by Wang Yinglin, and changed from Wang Xiu to several books with nine chapters.

The influence of later generations

Shu Shu Jiu Zhang is the inheritance and development of Jiu Zhang Arithmetic. It summarizes the main achievements of traditional mathematics in China in the Song and Yuan Dynasties and marks the peak of ancient mathematics in China. When it was a manuscript, it was successively included in Yongle Dadian and Sikuquanshu. 1842 was first printed and widely circulated among the people in China.

Qin's positive and negative cholesky decomposition and the great derivative method have long influenced the research direction of China's mathematics. The works of mathematicians, Li Rui, Zhang Dunren, Luo, Shi Yuechun and Huang Zongxian were all completed under the direct or indirect influence of the nine chapters. Qin's achievements also represent the mainstream and highest level of medieval mathematics development, and occupy a lofty position in the history of mathematics in the world.