Primary 4 Maths: Fractions
Primary 4 is where fraction understanding is built: mixed numbers, equivalent fractions, adding related fractions. Get this right and P5 gets easier.
Most schools typically cover this topic in Term 2, around weeks 1–4 — though every school sets its own sequence.
Primary 4 fractions is a foundation topic in the truest sense: everything your child does with fractions in P5 and P6 — and most of what they do with ratio and percentage — stands on what's built this year. The P4 scope is friendly: understanding mixed numbers and improper fractions, finding equivalent fractions, comparing fractions, and adding and subtracting related fractions (where one denominator divides the other, like thirds and sixths).
The single most important idea of the year is equivalence — that 2/8 and 1/4 are the same number wearing different clothes. Children who truly own equivalence find P5's unlike-fraction arithmetic a small step. Children who memorised their way past it hit a wall next year.
The mistakes to watch for
- Fractions treated as two separate whole numbers. Comparing 3/8 and 3/5 by declaring 8 "bigger". The fraction is one number, not a pair — and 3/5 is the larger here because fifths are bigger pieces than eighths.
- Equivalent fractions by adding. Turning 1/4 into 2/5 by adding 1 to top and bottom. Equivalence multiplies; it never adds.
- Mixed-number conversion slips. 2 3/8 should become 19/8 (2 × 8 + 3). A wrong conversion poisons every later step, so this needs to be fast and checked.
- Adding related fractions without converting first. 1/4 + 3/8 attempted as 4/12 instead of converting to 2/8 + 3/8 = 5/8.
Example question — mixed numbers
Try it: converting a mixed number
Express 2 3/8 as an improper fraction.
Show the worked solution
Each whole is 8 eighths, so 2 wholes = 16 eighths.
16/8 + 3/8 = 19/8.
Check: 19 ÷ 8 = 2 remainder 3 → 2 3/8. ✓
Try it: adding related fractions
Ali ate 1/4 of a pizza and his sister ate 3/8 of the same pizza. What fraction of the pizza was left?
Show the worked solution
Convert to the same denominator first: 1/4 = 2/8.
Eaten altogether: 2/8 + 3/8 = 5/8.
Left: 8/8 − 5/8 = 3/8 of the pizza.
How to practise this topic
At P4, seeing fractions matters as much as computing them — fraction discs, bar diagrams, and number lines aren't babyish props, they're how equivalence becomes real. In practice sessions, mix comparison questions in with arithmetic so your child keeps reasoning about size, not just executing procedures. And check retention after a few weeks: equivalence that's still solid in the next school term is the best predictor that P5 fractions will go smoothly.
What this topic covers
In the MOE syllabus, Primary 4 Fractions (P4-M-04) includes:
- Equivalent fractions
- Mixed numbers
- Improper fractions
- Conversion between mixed numbers and improper fractions
- Comparing and ordering fractions
- Addition of unlike fractions
- Subtraction of unlike fractions
- Fraction of a set of objects
- Fraction word problems
Before this topic
These topics feed into Fractions — if this one wobbles, check them first: Primary 4 Factors & Multiples.
Is Fractions actually solid?
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