2000 BC Babilonians use pi=25/8, Egyptians use pi=256/81
1100 BC Chinese use pi=3
200 AC Ptolemy uses pi=377/120
450 Tsu Ch'ung-chih uses pi=255/113
530 Aryabhata uses pi=62832/20000
650 Brahmagupta uses pi=sqrt(10)
1593 Romanus finds pi to 15 decimal places
1596 Van Ceulen calculates pi to 32 places
1699 Sharp calculates pi to 72 places
1719 Tantet de Lagny calculates pi to 127 places
1794 Vega calculates pi to 140 decimal places
1855 Richter calculates pi to 500 decimal places
1873 Shanks finds 527 decimal places
1947 Ferguson calculates 808 places
1949 ENIAC computer finds 2037 places
1955 NORC computer computes 3089 places
1959 IBM 704 computer finds 16167 places
1961 Shanks-Wrench (IBM7090) find 100200 places
1966 IBM 7030 computes 250000 places
1967 CDC6600 computes 500000 places
1973 Guilloud-Bouyer (CDC7600) find 1 Mio places
1983 Tamura-Kanada (HITACM-280H) compute 16 Mio places
1988 Kanada (HITAC M-280H) computes 16 Mio digits
1989 Chudnovsky finds 1000 Mio digits
1995 Kanada computes pi to 6000 Mio digits
1996 Chudnovsky computes pi to 8000 Mio digits
1997 Kanada determines pi to 51000 Mio digits
--David Blatner, the joy of pi