Comparing Fractions — Which Is Bigger? (Grades 4–5)
To compare two fractions is to decide which is larger (or whether they're equal).
Understanding comparing fractions
The easiest case is when the denominators (bottom numbers) are the same: then you just compare the top numbers, because the pieces are the same size. 3/5 is bigger than 2/5 because three fifth-sized pieces are more than two of them.
Key Idea
When the bottoms are different, the pieces are different sizes, so you can't compare top numbers directly. Two reliable moves: (1) rewrite both fractions with a common denominator (same-size pieces), then compare tops; or (2) compare each to a benchmark like 1/2 — e.g. 3/8 is less than 1/2 and 5/8 is more than 1/2, so 5/8 is bigger.
Seeing it in action
Worked example
Which is bigger, 3/5 or 2/5?
Same denominator (fifths), so compare tops: 3 > 2. → 3/5 is bigger.
Worked example 2: unlike denominators
Which is bigger, 2/3 or 3/4?
Common denominator of 3 and 4 is 12. Rewrite: 2/3 = 8/12, 3/4 = 9/12.
Compare tops: 9 > 8. → 3/4 is bigger.
A common mistake, and the fix
Thinking a bigger bottom number means a bigger fraction.
1/8 is smaller than 1/3, because cutting the same whole into 8 pieces makes each piece smaller. With different denominators, rewrite with a common denominator (2/3 = 8/12 and 3/4 = 9/12) or compare each fraction with 1/2.
Try a few
Compare 4/7 and 6/7.
same denominator.
Compare 1/2 and 5/8 using a benchmark.
it's more than half.
Compare 1/3 and 2/5.
1/3 = 5/15, 2/5 = 6/15.
Try it in Numeris.
A short lesson, then practice with feedback on every answer.
Put the reasoning on paper.
Try six fraction, angle, perimeter and area questions with explained answers, for grades 4–6.
Free printable · 3 pagesText version (screen-reader friendly): Draw it. Explain it. Math sample
Want a printable set too?
Practise this skill in Numeris, browse more free math pages, or join our optional resource updates.
All free math pages →