Zu Chongzhi, a Chinese mathematician, astronomer and engineer was born this year.  His main writings were lost so it is difficult to know exactly how great his mathematical achievements were.  Most of the knowledge on him is from various fragments and of historical materials.  He found pi to seven digits.  He recommended the use of 355/113 for a close approximation, and 22/7 for a rough approximation of pi.  Working with his father, he found the correct formula for the volume of a sphere.

Author: Charles DeBoer

References:
 http://www.interlochen.k12.mi.us/Math/AdvMath97.html, Author: Taoufik Nadji, Copyright: © 1997, Malek Physix Inc. All rights reserved. Revised: September 25, 1998.

http://www.nitk.edu.tw/~jochi/e3.htm

http://aleph0.clarku.edu/~djoyce/mathhist/china.html, Maintained by David E. Joyce (djoyce@clarku.edu) Department of Mathematics and Computer Science, Clark University
Initial work December, 1994. Latest update Sept 17, 1995.