🍰 Topics & explainers · 4 min read
Equivalent fractions in Class 4: different names, same amount
Why 1/2, 2/4 and 3/6 are the same amount — how Class 4 children find equivalent fractions, plus the NOT-equivalent trap from SOF IMO papers.
Equivalent fractions are different names for the same amount. Half a cake, two quarters of a cake and three sixths of a cake are the same slice of cake — 1/2, 2/4 and 3/6 are equivalent. This one idea unlocks comparing, adding and simplifying fractions, so it is worth getting rock solid in Class 4.
The idea in one minute
- Multiply the numerator and denominator by the same number and the fraction’s value does not change: 1/2 = 2/4 = 3/6 = 4/8.
- Dividing both by the same number also works — that is called simplifying: 6/9 = 2/3.
- The quick check for equivalence is cross-multiplication: 2/3 and 8/12 are equivalent because 2 × 12 = 24 and 3 × 8 = 24.
- You must do the same thing to top and bottom. Adding the same number to both is the classic mistake — 1/2 is not 2/3.
✏️ Warm-up: spot the equal half
Which fraction is equivalent to 1/2?
- A2/4
- B3/5
- C2/6
- D4/6
Show the answerAnswer: 2/4
Answer: 2/4. Multiply the top and bottom of 1/2 by 2: you get 2/4, the same amount. Checking the others: 3/5 is more than half, 2/6 simplifies to 1/3, and 4/6 simplifies to 2/3 — none of them equals a half.
✏️ Level up: find the missing numerator
Complete the equivalent fraction: 3/4 = ?/12
- A6
- B8
- C9
- D12
Show the answerAnswer: 9
Answer: 9. The denominator went from 4 to 12, so it was multiplied by 3. Do the same to the numerator: 3 × 3 = 9, giving 9/12. Check by simplifying: 9/12 ÷ 3 on top and bottom is 3/4. A child who multiplies by the wrong factor lands on 6 or 12.
✏️ Olympiad twist: which one is NOT equivalent?
Which of these is NOT equivalent to 2/3?
- A4/6
- B6/9
- C8/12
- D10/12
Show the answerAnswer: 10/12
Answer: 10/12. Test each against 2/3. 4/6 is 2/3 × 2/2, 6/9 is 2/3 × 3/3 and 8/12 is 2/3 × 4/4 — all equivalent. But 10/12 simplifies to 5/6, not 2/3. Cross-check: 2 × 12 = 24 while 3 × 10 = 30, so they are not equal. The olympiad twist is the word NOT — a rushing child ticks the first equivalent fraction they verify.
In LittleMathematicians’s Class 4 Fractions topic, equivalent fractions sit right before comparing fractions on the level path, and the adaptive questions add NOT-style twists as your child’s mastery grows. It is free during early access — a good topic for a first session.
Practice this the fun way
Adaptive levels, exam-pattern mocks and progress you can see — free during early access.
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