SME
Grade 4 Math · Problem type
Subtract fractions with like denominators
Use this for “5/8 − 2/8 =” and other like denominators.
Diagram
7/8: 7 jumps of 1/8 from 0.
This is an example. Type your own values to start a new problem.
First numerator
Denominator
−
Second numerator
Denominator
=
Numerator of the difference
Denominator
Formulas
7
8
−
3
8
=
4
8
Subtract the numerators; the denominator stays
Assumptions
•
Like denominators mean same-size parts: subtract the numerators, keep the denominator.
•
The first fraction is at least as big as the second. It can be more than 1 (13/5 − 4/5).
•
Denominators 2, 3, 4, 5, 6, 8, 10 and 12.
Step-by-step
WE KNOW
Denominator: 8
First numerator: 7
Second numerator: 3
FIND
numerator of the difference
Step 1 · Find numerator of the difference
7
8
−
3
8
=
?
8
Subtract the numerators; the denominator stays
Take the second numerator from the first. The denominator stays.
7
−
3
=
4,
so
4
8
Numerator of the difference = 4
Check
Put the numbers back in. Both sides should match.
7 − 3 = 4 ✓
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Fractions and mixed numbers
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Related lessons
Add and subtract fractions with like denominators
Main lesson
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