When rounding a number to the nearest hundred, you look at the digit in the tens place. In this case, the digit in the tens place is 7. Since 7 is greater than or equal to 5, you round up. Therefore, 570 rounded to the nearest hundred is 600.
Well, isn't that a happy little question! When we round 570 to the nearest hundred, we look at the tens place, which is 70. Since 70 is closer to 100 than it is to 0, we round 570 up to 600. Just a little adjustment to help our number fit in better with its hundred friends!