How to Add and Subtract Mixed Numbers

A mixed number combines a whole number and a fraction, like 2 1/3. The most reliable way to add or subtract mixed numbers is to convert them to improper fractions, do the arithmetic, then convert back.

Step by step

1. 1
   Convert each mixed number to an improper fraction
   2 1/3 becomes 7/3 (3 x 2 + 1 = 7), and 1 1/6 becomes 7/6.
2. 2
   Find a common denominator
   The common denominator of 3 and 6 is 6, so 7/3 = 14/6.
3. 3
   Add or subtract the numerators
   14/6 + 7/6 = 21/6.
4. 4
   Simplify and convert back
   21/6 simplifies to 7/2, which as a mixed number is 3 1/2.

Worked example

Add 2 1/3 + 1 1/6. Convert to improper: 7/3 + 7/6. Common denominator 6: 14/6 + 7/6 = 21/6 = 7/2 = 3 1/2.

Common mistakes to avoid

• Adding whole numbers and fractions separately without lining up denominators.
• Forgetting to borrow when subtracting and the fraction part is too small.
• Leaving the answer as an improper fraction when a mixed number was asked for.

Practice this skill

Try it yourself on the Add Fractions Calculator, generate a printable worksheet, or work through it one step at a time in guided practice.