British mathematician William Shanks famously took 15 years to calculate π to 707 digits, but made a mistake in the 528th digit, rendering all subsequent digits incorrect.
英國數學家威廉·謝克斯（英语：William Shanks）花了15年的時間計算π到小數707位，不過中間在第528位小數時出錯，因此後面的小數也都不正確。