5th-century mathematician
祖冲之 (Zu Chongzhi) calculated 3.1415926 < π < 3.1415927 — the most accurate value in the world for nearly 1,000 years. Earlier,
刘徽 (Liu Hui) used the
割圆术 (gēyuánshù, 'circle-cutting method') to approximate π ≈ 3.14, called the
徽率 in his honor.
