Original: The earliest known textually evidenced approximations date from around 1900 BC ; they are 25/8 ( Babylonia ) and 256/81 ( Egypt ) , both within 1 % of the true value .
Simplified: The first known approximations of pi are from around 1900 BC , and are 25/8 ( by the Babylonians ) and 256/81 ( by the Egyptians ) .