Input (grade 13): 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.
Output (grade 10): The first known approximations of pi are from around 1900 BC, and are 25/8 (by the Babylonians) and 256/81 (by the Egyptians).