Carolyn S. answered • 05/13/19

Patient and Effective Elementary Teacher

The rules of rounding state that if the digit before the one you want to round to is 4 or less, you round down. If it is 5 or greater, you round up. As we are looking to round to the nearest 10, you need to look at the ones place. If you round the 9 miles Bill rode on Saturday to the nearest 10, you would get 10 miles. The miles he rode on Sunday would be rounded to 0. We can see that 10 miles is quite far from 100, so saying that Bill rode 100 miles over the weekend would not be a reasonable answer.