* Significant figures are the digits in a number that contribute to its precision.
* Leading zeros (zeros before the first non-zero digit) are *not* significant.
* Trailing zeros (zeros after the last non-zero digit) are significant if they are to the right of a decimal point.
In 200.601:
* The first three digits (2, 0, and 1) are significant.
* The remaining digits (0, 0, and 1) are not significant.
Since the fourth digit (6) is greater than 5, we round the third significant digit (0) up to 1.
