Adding and Subtracting Fractions with the Same Denominator: Calm Guidance for Parents
19 October 2026
Adding and subtracting same denominator fractions
Adding and subtracting fractions with the same denominator is a key skill for 11+ maths. The process is straightforward: simply add or subtract the numerators, and keep the denominator the same.
How it works
For example, with 2/7 + 3/7, you add the numerators (2 + 3) to get 5, and keep the denominator as 7. So, 2/7 + 3/7 = 5/7. The same rule applies for subtraction: 5/9 − 2/9 = 3/9.
Simplifying answers
After adding or subtracting, check if the fraction can be simplified. For example, 3/9 can be simplified to 1/3 by dividing both the numerator and denominator by 3.
Key insight: Focus on the numerators
When the denominators are the same, children only need to work with the numerators. This can help build confidence before moving on to more complex fraction work.
Building strong foundations
Practising with same denominator fractions helps children understand the basics of fraction operations, making the transition to different denominators much easier later on.
