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Least Common Denominator - Printable Math Worksheets class 7 - Wayground

Least Common Denominator

Troy Henry

Created by Troy Henry

9 questions

7th Grade

Math

Updated Aug 2026

This Grade 7 mathematics worksheet focuses on finding the least common denominator for pairs of fractions with unlike denominators. Students complete 9 multiple-select questions, identifying the least common denominator for addition and subtraction problems such as 1/3 and 3/5, 6/7 and 1/2, and 5/6 and 3/4. The answer choices include possible denominators, helping students distinguish the least common denominator from an individual denominator, a sum, or a nonleast common multiple. Use this free printable worksheet to reinforce the denominator-selection step before students rewrite fractions or perform fraction operations. It works well for guided practice, independent review, or a quick check of whether students can identify common multiples accurately across both addition and subtraction examples. The worksheet includes a complete answer key for efficient checking and feedback, and its digital format can also support paperless practice on Wayground.

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Least Common Denominator

Total questions: 9

Name
Class
Date
1.

 13 + 35\frac{\text{1}}{\text{3}}\ +\ \frac{3}{5}  

a)

3

b)

5

c)

15

d)

25

2.

 67  − 12\frac{6}{7\ }\ -\ \frac{1}{2}  

a)

2

b)

7

c)

14

d)

9

3.

 16 + 25\frac{1}{6}\ +\ \frac{2}{5}  

a)

5

b)

6

c)

11

d)

30

4.

 59 − 13\frac{5}{9}\ -\ \frac{1}{3}  

a)

3

b)

9

c)

12

d)

27

5.

 18 + 34\frac{1}{8}\ +\ \frac{3}{4}  

a)

4

b)

8

c)

12

d)

32

6.

 57 − 23\frac{5}{7}\ -\ \frac{2}{3}  

a)

3

b)

7

c)

10

d)

21

7.

 25 + 14\frac{2}{5}\ +\ \frac{1}{4}  

a)

4

b)

5

c)

9

d)

20

8.

 56 − 34\frac{5}{6}\ -\ \frac{3}{4}  

a)

4

b)

6

c)

12

d)

24

9.

 34 − 37\frac{3}{4}\ -\ \frac{3}{7}  

a)

4

b)

7

c)

11

d)

28

WaygroundAnswer Key

Least Common Denominator

Total questions: 9

1.
c)

15

2.
c)

14

3.
d)

30

4.
b)

9

5.
b)

8

6.
d)

21

7.
d)

20

8.
c)

12

9.
d)

28

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FAQs

What does the Least Common Denominator worksheet cover?

This Grade 7 math worksheet practices finding the least common denominator for pairs of fractions with unlike denominators. Its 9 multiple-select questions use both addition and subtraction examples, requiring students to choose the least suitable common denominator from options such as 15, 14, 30, and 28 rather than simply selecting one of the original denominators.

How can I use this worksheet to teach finding the least common denominators?

First model how to list multiples of each denominator and identify the smallest value that appears in both lists. Then have students explain why the selected value is common to both denominators and why a larger option is not least, using the multiple-select choices on this worksheet for discussion. Assign the addition and subtraction items as guided practice before asking students to complete the full set independently.

What mistakes should I watch for on this least common denominator worksheet?

Watch for students choosing one original denominator, such as 3 or 5 in the 1/3 and 3/5 item, instead of a number shared by both denominators. Students may also select a common multiple that is not the least one, such as 25 instead of 15, or confuse the denominators with a result related to the fraction operation. The multiple-select format makes it important that students evaluate every option rather than selecting the first plausible number.

How do I assign and grade this least common denominator worksheet?

The worksheet is available as a printable PDF and as a digital quiz on Wayground, so you can use the 9 multiple-select questions for paper-based or online practice. It includes a complete answer key, and printable submissions can be graded by scanning student work with the Wayground for Teachers app. The printable version can also support classrooms that are reducing screen time.

How can I differentiate this worksheet for my students?

Use the worksheet’s Advanced Settings to adjust font spacing or choose a larger font size so the fraction pairs and multiple-select options are easier to read. You can also enable a dyslexia-friendly font or translate the worksheet into another language while keeping the least-common-denominator questions and answer choices intact.

Where can I find more worksheets like this on Wayground?

Wayground offers a broad collection of free printable worksheets and practice problems across subjects, with downloadable PDFs and answer keys to help students build essential skills and concepts. Browse more resources at https://wayground.com/en-us/worksheets.

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