What is 2.053 minus 2.048?

• A. 0.0005
• B. 0.050
• C. 0.005
• D. 0.503

Answer: (C)

Subtracting decimals works by lining up the decimal points and working from right to left. For 2.053 minus 2.048, compare the fractional parts: 0.053 minus 0.048. Since 3 thousandths is less than 8 thousandths, borrow 1 thousandth from the hundredths place. That makes the hundredths go from 5 to 4 and the thousandths go from 3 to 13. Now 13 − 8 = 5 thousandths. Then 4 − 4 = 0 in the hundredths, and 0 − 0 = 0 in the tenths. So the fractional part is 0.005. The whole difference is 0.005. A quick check shows 0.053 − 0.048 = 0.005, which matches the difference between the two numbers.