Finding Common Denominators in Fractions

This video tutorial explains two methods for adding fractions with unlike denominators. The first method involves finding common multiples to determine a common denominator, demonstrated with examples. The second method uses multiplication of denominators to quickly find a common denominator. Both methods are illustrated with step-by-step examples, and the video also touches on converting improper fractions to mixed numbers.

What is the first step in adding fractions with unlike denominators?

• Find a common denominator

• Find a common numerator

• Multiply the numerators

• Subtract the denominators

In the first example, what are the denominators of the fractions being added?

• 5 and 6

• 4 and 5

• 3 and 4

• 2 and 3

What is the common denominator found for the fractions 3/4 and 2/3?

• 10

• 12

• 6

• 8

What is the sum of the fractions 9/12 and 8/12?

• 15/12

• 16/12

• 17/12

• 18/12

In the second example, what are the denominators of the fractions being added?

• 8 and 9

• 7 and 8

• 10 and 12

• 12 and 8

What is the common denominator found for the fractions 7/12 and 5/8?

• 20

• 32

• 24

• 28

What is the sum of the fractions 14/24 and 15/24?

• 31/24

• 30/24

• 29/24

• 28/24

What is an alternative method to find a common denominator?

• Add the numerators

• Subtract the denominators

• Multiply the denominators

• Divide the numerators

Using the multiplication method, what is the common denominator for 3/4 and 2/3?

• 6

• 8

• 10

• 12

Using the multiplication method, what is the common denominator for 7/12 and 5/8?

• 72

• 84

• 108

• 96