Adding & Subtracting Fractions (Same Denominator)
This topic covers 5 learning steps, guiding your child from the basics through to confident problem-solving. Each step includes a worked example and adaptive practice questions.
What Your Child Will Learn
- Equal Parts Intro
Identify equal parts of a whole using visuals - Add Fractions (Same Denominator)
Add two fractions that share the same denominator - Subtract Fractions (Same Denominator)
Subtract fractions with the same denominator - Mixed Add & Subtract
Solve problems mixing addition and subtraction of same-denominator fractions - Challenge — Word Problems
Solve multi-step word problems with same-denominator fractions
Worked Example
Chef Whiskers says:
Chef Whiskers cuts a fish pie into 6 equal slices. He eats 2 slices. What fraction did he eat?
- Count the total slices: 6 — that is our denominator (bottom number).
- Count the slices eaten: 2 — that is our numerator (top number).
- Write the fraction: 2/6.
Answer: 2/6
Common Mistakes
- Adding the denominators as well as the numerators (e.g. 2/5 + 1/5 = 3/10 instead of 3/5)
When fractions share the same denominator, only add or subtract the numerators — the denominator stays the same. Think of it as counting slices: 2 fifths + 1 fifth = 3 fifths, just like 2 apples + 1 apple = 3 apples. - Thinking that 3/5 is smaller than 2/5 because the child confuses numerator and denominator roles
The numerator (top) counts how many parts you have. The denominator (bottom) says how big each part is. 3/5 means "3 out of 5 equal parts" — more parts than 2/5.
Tips for Parents
- Cut a pizza or cake into equal slices and practise adding portions: "You ate 2 eighths and your brother ate 3 eighths — how much pizza has been eaten altogether?"
- Use a bar of chocolate divided into equal squares. Count how many squares each person eats, then describe it as a fraction of the whole bar.
- Draw fraction strips on paper — colour in different amounts and add them together visually so your child sees that the denominator does not change.
- Ask questions like "If I drink 1/4 of the juice and you drink 2/4, what fraction have we drunk in total?" Use a real bottle to check.
Key Words
- Numerator — The top number in a fraction — it tells you how many parts you have.
- Denominator — The bottom number in a fraction — it tells you how many equal parts the whole is divided into.
- Same denominator — When two fractions have the same bottom number, like 2/7 and 3/7.
- Unit fraction — A fraction with 1 on top — like 1/3 or 1/8.
- Proper fraction — A fraction where the top number is smaller than the bottom — like 3/5.
Where This Fits
Before this topic: Children should understand what fractions mean, recognise unit fractions (1/2, 1/3, 1/4), and know that the denominator tells how many equal parts the whole is split into.
After this topic: Adding and subtracting fractions with the same denominator prepares children for working with unlike denominators in Year 5, where they need to find a common denominator before combining fractions.
How MathCraft Teaches This
In MathCraft, Adding & Subtracting Fractions (Same Denominator) is taught through the Number & Fractions adventure track. Your child follows guided lessons with friendly characters, works through examples step by step, then practises with questions that adapt to their level.
The adaptive engine tracks mastery across all 5 steps, revisiting concepts your child finds tricky and advancing when they're ready. Parents can see detailed progress in the Parent Dashboard.
Practise Adding & Subtracting Fractions (Same Denominator) with MathCraft
Step-by-step lessons, worked examples, and adaptive practice — all wrapped in an adventure game your child will love.
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