Liu Hui (about AD 225-295) was born in zouping county, Shandong Province, a mathematician in this period and one of the founders of China's classical mathematical theory. He is a very famous mathematician in the history of Chinese mathematics. His representative works "Nine Arithmetic Notes" and "Arithmetic on the Island" are China's most precious mathematical heritage. Liu Hui has quick thinking and flexible methods, and advocates both reasoning and intuition. He is the first person who China explicitly advocated to demonstrate mathematical propositions by logical reasoning. Liu Hui's life is a life of hard exploration of mathematics. Although the status is low, but the personality is noble. He is not a mediocre man who pursues fame and fortune, but a great man who never tires of learning. He left us a valuable fortune. & gt Liu Hui was the most outstanding mathematician in the world in the 3rd century A.D. His Nine Chapters Arithmetic Notes written in 263 A.D. and his later calculations on the island are the most precious mathematical heritages of China, thus establishing his immortal position in the history of Chinese mathematics. & gt Liu Hui's mathematical works are rarely passed down to later generations, and they are all copied for a long time. & gt's main works are: Nine Chapters of Arithmetic Notes (volume 10); The weight difference (1) was renamed as island calculation in the Tang Dynasty. Chapter 9 gravity difference Map Volume L. Unfortunately, the latter two were lost in the Song Dynasty. > Nine Chapters of Arithmetic was written in the early Eastern Han Dynasty, and * * * has 246 solutions. In solving simultaneous equations, calculating four fractions, calculating positive and negative numbers, calculating the volume and area of geometric figures and many other aspects, it is among the advanced in the world. & gt However, due to the primitive solution and the lack of necessary proof, Liu Hui made supplementary proof. In these proofs, his creative contributions in many aspects are shown. He was the first person in the world to put forward the concept of decimal, and used decimal to represent the cube root of irrational numbers. In algebra, he correctly put forward the concept of positive and negative numbers and the principle of addition and subtraction, and improved the solution of linear equations. In geometry, "secant" is put forward, that is, the method of finding the area and perimeter of a circle by using inscribed or circumscribed regular polygons to exhaust the circumference. He scientifically obtained the result that pi = 3. 14 16 by using secant technology. He cut a circle from a circle with a diameter of 2 feet by connecting a regular hexagon, and then he got a regular polygon of 12 and a regular polygon of 24 ... The thinner he cut, the smaller the difference between the area of the regular polygon and the area of the circle. In his original words, it is "cut carefully, and the loss is not big. If you cut again, there will be no loss." He calculated the area of 3072 polygons and verified this value. The scientific method of calculating pi put forward by Liu Hui has established China's leading position in the world for more than 1000 years. & gt