What is 2.5 + 3.75?

What is 2.5 + 3.75?

• A. 5.75
• B. 6.25
• C. 6.0
• D. 6.5

Answer: (B)

When you add decimals, line up the decimal points so each place value matches, and treat tenths and hundredths like regular digits. Write 2.5 as 2.50 so both numbers have two decimal places. Then add from the right: in the hundredths place, 0 plus 5 equals 5; in the tenths place, 5 plus 7 equals 12, so you write down 2 and carry 1 to the whole number part; in the ones place, 2 plus 3 plus the carried 1 equals 6. The sum is 6.25. Keeping the decimal points aligned is what makes this correct, rather than 6.0, 5.75, or 6.5.

When you add decimals, line up the decimal points so each place value matches, and treat tenths and hundredths like regular digits. Write 2.5 as 2.50 so both numbers have two decimal places. Then add from the right: in the hundredths place, 0 plus 5 equals 5; in the tenths place, 5 plus 7 equals 12, so you write down 2 and carry 1 to the whole number part; in the ones place, 2 plus 3 plus the carried 1 equals 6. The sum is 6.25. Keeping the decimal points aligned is what makes this correct, rather than 6.0, 5.75, or 6.5.