Significant Digits:
A way of describing how precisely a number is written.

In the Olympics, the times given to runners in the 100-meter dash are given up to the nearest 100th of a second. This allows for 1st, 2nd, and 3rd place winners to be awarded medals instead of "ties" because often the top two or three runners will have the same time to the nearest tenth of a second. Therefore, the more significant digits used, the more accurate the time.