Add 3 1/4 and 2 2/3. What is the sum in mixed number form?

Add 3 1/4 and 2 2/3. What is the sum in mixed number form?

• A. 6
• B. 5 1/2
• C. 5 11/12
• D. 5 7/12

Answer: (C)

When adding mixed numbers, add the whole numbers and the fractional parts separately, using a common denominator for the fractions. Whole numbers: 3 + 2 = 5. Fractions: 1/4 + 2/3. The least common multiple of 4 and 3 is 12, so convert: 1/4 = 3/12 and 2/3 = 8/12. Add to get 11/12. Combine them: 5 and 11/12, or 5 11/12. For a quick check, convert to improper fractions: 3 1/4 = 13/4 and 2 2/3 = 8/3. Their sum is 13/4 + 8/3 = 71/12 = 5 11/12. This matches.

When adding mixed numbers, add the whole numbers and the fractional parts separately, using a common denominator for the fractions.

Whole numbers: 3 + 2 = 5.

Fractions: 1/4 + 2/3. The least common multiple of 4 and 3 is 12, so convert: 1/4 = 3/12 and 2/3 = 8/12. Add to get 11/12.

Combine them: 5 and 11/12, or 5 11/12.

For a quick check, convert to improper fractions: 3 1/4 = 13/4 and 2 2/3 = 8/3. Their sum is 13/4 + 8/3 = 71/12 = 5 11/12. This matches.