In 1910, the population of Seattle, Washington, was 237,194. In 2010, the population had grown to 608,660. By about how much did the population increase from 1910 to 2010? Round each number to the nearest hundred.

You subtrscy the bigger number (2010's population) by the smaller one (1910's population). 237194-608660 = 371,466.

When you round to the 100's you check the 10's place. If 5 or higher add a 1 to the hundreds place, and make the 1's and 10's place 0. If lower don't add anything and make the 1's and 10's place into 0s.

When you round it, you will get 371,400