Complex sentence: Qin Jiushao (ca.1202--1261), courtesy name Daogu (道古), was a Chinese mathematician born in Ziyang, Sichuan, his ancestry was from Shandong, and is now regarded as one of the greatest mathematicians of the 13th century.
Split into simpler sentences: Qin Jiushao (ca.1202--1261), courtesy name Daogu (道古), was a Chinese mathematician. He was born in Ziyang, Sichuan, his ancestry was from Shandong, and is now regarded as one of the greatest mathematicians of the 13th century.