Subtract 2 1/3 minus 5/6. What is the result in mixed-number form?

• A. 2
• B. 1 1/2
• C. 1 3/4
• D. 1 1/3

Answer: (B)

Subtracting mixed numbers works best by turning everything into fractions with the same denominator, then subtracting and finally converting back to a mixed number. First, rewrite 2 1/3 as an improper fraction: 7/3. The other fraction is 5/6. Use a common denominator, which for 3 and 6 is 6, and convert 7/3 to 14/6. Now subtract: 14/6 − 5/6 = 9/6. This simplifies to 3/2, which is 1 1/2 in mixed-number form. You can also see this by borrowing: take 1 from the 2 to give the fractional part enough to subtract 5/6, turning it into 1 4/3 minus 5/6; 4/3 is 8/6, so 8/6 − 5/6 = 3/6 = 1/2, and adding back the borrowed 1 gives 1 1/2.