Subtracting Improper Fractions with Different Denominators: Step-by-Step Example
22 October 2026
When subtracting improper fractions with different denominators, it helps to work through each step slowly. This example shows how to make the denominators the same before you subtract.
Worked example
Subtract 7/4 − 5/3
Step 1: Find a common denominator for 4 and 3. The lowest is 12.
Step 2: Change both fractions to have denominator 12.
7/4 = (7 × 3)/(4 × 3) = 21/12
5/3 = (5 × 4)/(3 × 4) = 20/12
Step 3: Subtract the numerators. 21/12 − 20/12 = 1/12
The correct answer is 1/12.
| Step | Fraction | Equivalent Fraction |
|---|---|---|
| Start | 7/4 | |
| Start | 5/3 | |
| Convert | 7/4 | 21/12 |
| Convert | 5/3 | 20/12 |
| Subtract | 21/12 - 20/12 | 1/12 |
Now your child can spot when two improper fractions have different denominators and use a common denominator to subtract them. More practice questions like this are ready to help build confidence. The maths.com uk approach keeps each step clear and manageable.
