Subtract 128.49 from 264.72 and you end up getting to answer of 136.23. The tenths place is the number directly after the decimal. In your answer from the subtraction problem, the tenths place is the number 2. In order to round, it's easiest to look at the number directly to the right of the number that you are trying to round. Look at the number 3, directly to the right of the number in the tenths place. Since 3 is less than 5, the number that you are rounding stays the same. If the number were to be above 5, then the number that you are trying to round would go up 1 in value. In the end, your answer would be C. 136.2. I hope this makes some type of sense and helps you in the future!