Name
LESSON
5
Common Denominators and
Equivalent Fractions
1
5.3
OBJECTIVE Find a common denominator or a least common denominator to write equivalent fractions.
You can find a common denominator of two fractions.
A common denominator of two fractions is a common multiple
of their denominators.
7
Find a common denominator of 1_6 and __
10 . Rewrite the pair of
fractions using a common denominator.
Step 1 Identify the denominators.
The denominators are 6 and 10.
Step 2 List the multiples of the greater denominator, 10.
Multiples of 10: 10, 20, 30, 40, 50, 60, ...
Step 3 Check if any of the multiples of the greater denominator
are evenly divisible by the other denominator.
Both 30 and 60 are evenly divisible by 6.
7
Common denominators of 1_6 and __
10 are 30 and 60.
© Houghton Mifflin Harcourt Publishing Company
Step 4 Rewrite the fractions with a denominator of 30.
Multiply the numerator and the denominator of each fraction
by the same number so that the denominator results in 30.
× 5 = ___
5
7 × 3 = ___
1= 1
7 = _______
21
__
______
___
6
6 × 5 30
10
10 × 3 30
Use a common denominator to write an equivalent fraction for
each fraction.
5 , __
2
5
__, __
1. ___
2. 3
12 9
8 6
common denominator:
2, __
1
3. __
9 6
common denominator:
Number and Operations
common denominator:
3, ___
9
4. __
4 10
common denominator:
9
Name
1
Common Denominators and
Equivalent Fractions
5.3
Use a common denominator to write an equivalent
fraction for each fraction.
1, __
1 common
1. __
5 2
denominator: 10
1, __
2 common
2. __
4 3
denominator:
5, __
1 common
3. __
6 3
denominator:
1, __
3 common
5. __
2 8
denominator:
1, __
1 common
6. __
6 4
denominator:
Think: 10 is a multiple of 5 and 2.
Find equivalent fractions with a
denominator of 10.
3, __
1 common
4. __
5 3
denominator:
Use the least common denominator to write an equivalent
fraction for each fraction.
1 , __
3
8. ___
12 8
5, ___
2
9. __
9 15
Problem Solving
10. Ella spends 2_3 hour practicing the
piano each day. She also spends
1
_ hour jogging. What is the least
2
common denominator of the
fractions?
10
11. In a science experiment, a plant
grew 3_4 inch one week and 1_2 inch
the next week. Use a common
denominator to write an equivalent
fraction for each fraction.
Lesson 5
© Houghton Mifflin Harcourt Publishing Company
5, __
2
7. __
6 9