劉徽的成就，除了圓周率算法，求解線性方程組（高斯消元法），等冪等積定理，更偉大的是（據English Wiki）

Through his work in the Nine Chapters, he could have been the first mathematician to discover and compute with negative numbers; definitely before Ancient Indian mathematician Brahmagupta （排23）started using negative numbers.

劉徽生活的魏晉時期，社會動亂但思想活躍。以後中國數學就走下坡路了。