What is 347 plus 298?

• A. 625
• B. 645
• C. 665
• D. 600

Answer: (B)

Adding by place value helps you see what’s happening in each column. Start with the ones: 7 plus 8 equals 15, so you write down 5 and carry over 1 to the tens. In the tens column, 4 plus 9 is 13, and with the carried 1 it becomes 14, so you write down 4 and carry 1 to the hundreds. In the hundreds column, 3 plus 2 is 5, plus the carried 1 makes 6. Put the digits together and you get 645. A quick check is to round 298 to 300: 347 + 300 = 647, then subtract 2 to adjust for the difference, giving 645. The other numbers don’t match this final result.