Fractions and common denominators

Ask yourself if the larger fraction is a multiple of the smaller fractions. If you answer yes, use the larger fraction for the common denominator.

If the answer is no, write the multiples of the larger fraction. As you write each multiple, ask if it is also a multiple of the smaller fraction. If you answer yes, that is your common denominator.

What is the common denominator for these two fractions

5/9

4/12

• 12

• 9

• 36

• 24

Ask yourself if the larger fraction is a multiple of the smaller fractions. If you answer yes, use the larger fraction for the common denominator.

If the answer is no, write the multiples of the larger fraction. As you write each multiple, ask if it is also a multiple of the smaller fraction. If you answer yes, that is your common denominator.

What is the common denominator for these fractions

2/8

4/6

• 8

• 24

• 12

• 6

Ask yourself if the larger fraction is a multiple of the smaller fractions. If you answer yes, use the larger fraction for the common denominator.

If the answer is no, write the multiples of the larger fraction. As you write each multiple, ask if it is also a multiple of the smaller fraction. If you answer yes, that is your common denominator.

What is the lest common denominator for these fractions

2/3

3/9

• 3

• 9

• 18

• 27

Ask yourself if the larger fraction is a multiple of the smaller fractions. If you answer yes, use the larger fraction for the common denominator.

If the answer is no, write the multiples of the larger fraction. As you write each multiple, ask if it is also a multiple of the smaller fraction. If you answer yes, that is your common denominator.

What is the least common denominator?

2/5

4/10

• 10

• 20

• 30

• 40