Subtracting Fractions with Like Denominators
Twenty-four subtraction problems where both fractions have the same denominator. Part A uses fractions less than 1. In Part B the first fraction is greater than 1, such as 13/9, which prepares students for subtracting mixed numbers.
- Grade
- Grade 4
- Problems
- 24
- Time
- About 15 minutes
- Standard
- 4.NF.B.3a
Download
Download PDF (US Letter) Download PDF (A4)Two pages: the worksheet, then the answer key. No sign-up needed.
Part A: Fractions less than 1 Subtract. Write the answer as a fraction.
- 34−14=24
- 410−110=310
- 29−19=19
- 57−17=47
- 812−312=512
- 45−35=15
- 812−212=612
- 45−15=35
- 28−18=18
- 26−16=16
- 27−17=17
- 34−24=14
- 1112−312=812
- 23−13=13
- 37−27=17
- 510−110=410
- 312−112=212
- 79−49=39
Part B: Starting above 1 Subtract. Write the answer as a fraction.
- 159−29=139
- 87−77=17
- 139−119=29
- 1410−510=910
- 86−76=16
- 169−89=89
Tips for teachers and parents
- Subtract the top numbers and keep the bottom number: 7 ninths take away 4 ninths leaves 3 ninths.
- Have students check each answer by adding it back: the answer plus the fraction taken away should give the starting fraction.
- For Part B, students can picture the first fraction as one whole plus some extra parts, then take away.
- Every answer is greater than zero, so if a student gets zero or a negative number, the numbers were swapped.
Common mistakes
- Subtracting the denominators as well, which gives a 0 on the bottom. The size of the pieces does not change.
- Subtracting the smaller top number from the bigger one in the wrong order. The first fraction is always the larger one on this sheet.
What to practice next
Mixed numbers and improper fractions connect Part B answers to numbers like 1 4/9.
Frequently asked questions
How do you subtract fractions with the same denominator?
Subtract the numerators and keep the denominator. For example, 5/8 − 2/8 = 3/8.
Do the answers need to be simplified?
No. The answer key keeps the same denominator, such as 6/12. Simplified answers are also correct.
Is there an answer key?
Yes, page 2 has all 24 answers.