What is 3.6 minus 1.9?

• A. 1.5
• B. 1.7
• C. 2.5
• D. 0.7

Answer: (B)

Subtracting decimals works by lining up the decimal points and handling each place value. For 3.6 minus 1.9, borrow from the ones place to fix the tenths. The 3 becomes a 2, and the tenths become 16. 16 minus 9 gives 7 tenths. Then 2 (the adjusted ones) minus 1 equals 1. So the difference is 1.7. This result comes directly from the place-value borrowing process in decimal subtraction. The other numbers would result from subtracting different amounts, but with 3.6 and 1.9, you get 1.7.