Answer: C
First simplify the two terms separately. In order to add or subtract decimals, simply line up the decimal points as you would if the decimal points were not there. You can make all numbers line up evenly by adding zeros to the right of the ones that need them.
8.0 3.0
- 0.5 - 0.5
_________
7.5 2.5
Before you divide decimals, you have to remove decimals. All you have to do is to move the decimal point all the way to the right, but remember to move decimal point the same number of spaces both in the dividend and the divisor.
7.5/2.5 = 75/25 = 3
Key takeaway: If the decimal point is missing in a number, put it to the right of the number and line up evenly by adding zeros to the right. When handling decimals, the only tricky part is remembering where to put the decimal.