Find Common Denominators

Rename 4/10 and 3/8 using 40 as the common

10 denominator.

Multiply the numerator and denominator

by the same nonzero number.


So,16/40 and 15/40 is one way to rename 4/10

and 3/8 using a common denominator.

Step 2

Find a common denominator for 4/10 and 3/8

List multiples of the denominators 10 and 8.

Then look for a common multiple.

10: 10, 20, 30 40

8: 8, 16, 24,3 , 40

The number 40 can be used as the

common denominator.

Step 1

Find Common Denominators

​common denominator

multiples of 9

multiples of 3

​common denominator

multiples of 5

multiples of 4

​common denominator

multiples of 3

multiples of 7

​common denominator

multiples of 5

multiples of 12

Multiple Choice

What is the least common denominator for

$$\frac{1}{2}\ and\ \frac{4}{7}$$  

• 14

• 12

• 10

• 8

Multiple Choice

What is the least common denominator for

$$\frac{3}{8}\ and\ \frac{1}{6}$$  

• 16

• 24

• 36

• 48

Multiple Choice

What is the least common denominator for

$$\frac{3}{8}\ and\ \frac{1}{6}$$  

• 16

• 24

• 36

• 48