Revision notes
Discover why 12, 24 and 48 are the same amount, then simplify and compare fractions with confidence.
Tunde breaks his chocolate bar into 3 equal pieces and eats 2. Aisha breaks the same size bar into 6 pieces and eats 4. Who ate more? Neither — they ate exactly the same amount!
Equivalent fractions are fractions that are worth the same amount, like 23 and 46.
If you cut every piece of 23 into 2 smaller pieces, you get 6 pieces in the whole and 4 of them are shaded. The amount shaded has not changed.
That is why we multiply the top and the bottom by the same number. Doing this to 23 gives 46 (× 2), 69 (× 3) and 812 (× 4).
🔑 Key idea: Multiply (or divide) the top AND bottom by the same number — the value stays the same.
Going the other way, we divide the top and bottom by the same number to simplify: 1218 ÷ 6 on top and bottom gives 23.
Divide by the HCF of the top and bottom to reach the lowest terms in one step. A fraction is in lowest terms when the top and bottom have no common factor except 1.
Careful: adding the same number to top and bottom does NOT give an equivalent fraction. 12 and 23 are not equal.
🔑 Key idea: Lowest terms: divide top and bottom by their HCF.
To compare 34 and 56, change both to the same denominator. The LCM of 4 and 6 is 12.
34 = 912 and 56 = 1012. Now the pieces are the same size, so just compare the numerators: 1012 is bigger.
So 56 > 34.
🔑 Key idea: Same denominator → compare numerators.
Find the missing number: 16 = ? / 30
Step 1: Find the multiplier
6 × 5 = 30
Step 2: Multiply the top by the same number
1 × 5 = 5
16 = 530
Why? Multiplying top and bottom by the same number cuts the same amount into more, smaller pieces — the value does not change.
Answer: 5
Ready to check you've got it? Scroll up and work through the lesson: the interactive visuals, practice questions and mastery check are all there.