Liu Hui was a great Chinese
mathematician in the third century. He lived in a time of serious political
turbulence in China. The country was split into three kingdoms and Liu Hui was
an official of the Kingdom of Wei. After years of war, the Kingdom of Wei came
out on top and began to revive literary and scientific classics.

Liu Hui was most famous for his annotated
text of *Jiuzhang Suanshu* (*Nine Chapters on the Mathematical Art*),
which came into being in the Eastern Han Dynasty (25-220). The book consists of
9 chapters containing 246 questions with their solutions and procedures. Each of
9 chapters focuses on a separate part of daily mathematics. Many data recorded
in the book were advanced in the world at that time, but some of the solutions
lacked proof. In 263, Liu Hui annotated the book, giving full proof to the
solutions and formulas in the book while correcting the errors.

Liu Hui was the first person to put forward
the concept of decimal number in the world. He also raised and defined a number
of mathematical concepts, including area, power and equation. Besides, he
approximated* *pi* *by approximating circles polygons, doubling the
number of sides to get better approximations. From 96 and 192 sided polygons, he
approximates* *pi* *as 3.141014 and suggested 3.14 as a practical
approx. This is the most accurate estimate of ancient mathematicians.

He also compiled the *Haidao Suanjing*
(*Sea Island Mathematical Manual*) which consisted of 9 measurement
problems. The originality, complexity and representativeness of the problems
impressed the peers in the West.

Liu Hui was more devoted into solving the
problems on area and volume than any of his predecessors and made great
achievements in this field. He is considered one of the greatest mathematicians
in China.