2. The number of nine chapters in the book is four to seven years in Song Chun (A.D. 1244 to 1247). During Qin's three years in Huzhou, he edited and sorted out the long-term accumulated mathematical knowledge and research results, and wrote the world-famous mathematical masterpiece "Several Books and 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.

This book is not only abundant in quantity, but also first-class in quality. Historically, Qin's Nine Chapters of Qin Memorial Hall can be compared with Nine Chapters Arithmetic. From a global perspective, Qin's Nine Chapters is also a well-deserved masterpiece of world mathematics. Qin not only won great honor for China, but also made outstanding contributions to world mathematics.