fl. 6 B.C.-A.D.23

Chinese scholar and astronomer credited as the first to use decimal fractions. Liu Hsin is also known for a treatise on the calendar and for his calculation of π at 3.1547. About five centuries later another Chinese mathematician, Tsu Ch'ung-chih (Zu Chongzhi; 429-500), established the formula of 355/113, which is very close to the number—3.141592 followed by an infinite number of digits—accepted today.