What is 5.520 minus 5.488?

• A. 0.052
• B. 0.009
• C. 0.320
• D. 0.032

Answer: (D)

To subtract decimals cleanly, line up the decimal points and borrow across places as needed. Here the whole-number parts are the same, so focus on the decimal parts: 0.520 minus 0.488.

Subtract thousandths first: 0 cannot minus 8, so borrow from the hundredths. The hundredths digit drops from 2 to 1, and the thousandths become 10; 10 − 8 = 2.

Next, hundredths: 1 cannot minus 8, so borrow from the tenths. The tenths digit drops from 5 to 4, and the hundredths become 11; 11 − 8 = 3.

Tenths: 4 − 4 = 0. Ones: 5 − 5 = 0.

So the result is 0.032, which is 32 thousandths.