Qin Jiushao

Qin Jiushao (about 1202 to 1261) was a Chinese mathematician, meteorologist, inventor, politician and writer of the Southern Song dynasty. Born in Ziyang, Sichuan, to a family from Shandong, he held a series of bureaucratic posts in several provinces. In 1247 he wrote the Mathematical Treatise in Nine Sections, which covers indeterminate equations, the numerical solution of polynomial equations up to the tenth degree, surveying and military matters, and a general form of the Chinese remainder theorem. He is credited with the method of polynomial evaluation now called Horner method, with a triangle area formula equivalent to Heron formula, and with inventing Tianchi basins, a type of rain gauge. He also introduced the zero symbol into written Chinese mathematics.