Comparing fractions (age 9+)
Compare and order fractions with different numerators and denominators by creating common denominators/numerators or comparing to a benchmark such as 1/2; justify conclusions with visual models
What a learner can do afterwards
- Compare 3/8 and 5/12 by finding a common denominator of 24
- Order 2/3, 3/5, and 7/10 from smallest to largest
- Use the benchmark 1/2 to decide that 5/8 > 3/7
1 · Read
You already know how to compare fractions that share the same bottom number, or that sit near one-half. Now you'll compare fractions where the top and bottom numbers are both different, like 3/8 and 5/12. The trick is to rewrite both fractions with a common denominator, or check each one against the benchmark 1/2.
Compare 3/8 and 5/12. Both 8 and 12 divide evenly into 24, so rewrite each fraction with 24 as the denominator: 3/8 becomes 9/24, and 5/12 becomes 10/24. Since 10/24 is more than 9/24, 5/12 is the bigger fraction.
If you're not sure, draw a quick picture or check both fractions against one-half. If one fraction is under 1/2 and the other is over 1/2, you already know which is bigger.
To compare fractions with different tops and bottoms, make a common denominator or check each one against one-half.
2 · Watch
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Where it sits
Where this leads
Jobs that lean on this skill. Follow one to see everything it is built on.
16 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.