Subtracting an Improper Fraction from a Mixed Number: Step-by-Step Example
22 October 2026
Subtracting an improper fraction from a mixed number can seem tricky at first. Helping your child see each step clearly will make it much easier to understand.
Here is a step-by-step example to guide you through the process. This method is perfect for children preparing for 11+ maths.
Worked example
Subtract 5/3 from 3 1/4.
Step 1: Change 3 1/4 to an improper fraction.
3 × 4 = 12. 12 + 1 = 13. So, 3 1/4 = 13/4.
Step 2: Find a common denominator for 13/4 and 5/3.
The denominators are 4 and 3. The lowest common denominator is 12.
Step 3: Rewrite both fractions with denominator 12.
13/4 = (13 × 3) / (4 × 3) = 39/12.
5/3 = (5 × 4) / (3 × 4) = 20/12.
Step 4: Subtract the fractions.
39/12 − 20/12 = 19/12.
Step 5: Change 19/12 back to a mixed number.
12 goes into 19 once, with 7 left over. So, 19/12 = 1 7/12.
The answer is 1 7/12.
| Step | Fraction 1 | Fraction 2 | Result |
|---|---|---|---|
| Start | 3 1/4 | 5/3 | |
| Improper fractions | 13/4 | 5/3 | |
| Common denominator | 39/12 | 20/12 | |
| Subtract | 39/12 | 20/12 | 19/12 |
| Mixed number | 1 7/12 |
Now your child can spot when a question asks them to subtract an improper fraction from a mixed number. They will know how to turn mixed numbers into improper fractions and work with common denominators.
There are more practice questions just like this, so your child can build confidence with subtracting improper fractions from mixed numbers.
