Exploring Common Denominators with Example Problems

This video tutorial covers the concept of common denominators in fractions. It begins with an introduction to what common denominators are and why they are important. The lesson reviews using factors to find common denominators and introduces a method of multiplying fractions to achieve common denominators when factors are not applicable. Several examples are provided to illustrate the process, and the video concludes with a final example and a summary of the key points discussed.

What is a common denominator?

• The top number of a fraction

• A number that is a factor of both numerators

• The same bottom number in two or more fractions

• A number that is a multiple of both numerators

Why can't we use the method from the previous lesson when the denominators are not factors of each other?

• Because the fractions are already simplified

• Because the denominators are not divisible by each other

• Because the fractions are improper

• Because the numerators are too large

What is the first step in finding a common denominator when the denominators are not factors of each other?

• Add the fractions directly

• Multiply the fractions by 2

• Multiply each fraction by the denominator of the other fraction

• Subtract the smaller denominator from the larger one

In the example, what do you get when you multiply 2 by 8?

• 12

• 10

• 14

• 16

What is the common denominator for the fractions 2/3 and 4/8 after applying the method?

• 48

• 32

• 16

• 24

What is the result of multiplying 1/2 by 5/5?

• 1/5

• 10/5

• 5/10

• 2/5

What is the common denominator for the fractions 1/2 and 2/5?

• 20

• 10

• 15

• 5

In the final example, what do you get when you multiply 3 by 8?

• 24

• 40

• 16

• 32

What is the common denominator for the fractions 3/7 and 5/8?

• 35

• 48

• 56

• 40

Why is it important to have common denominators when adding or subtracting fractions?

• To be able to add or subtract the fractions correctly

• To make the numerators equal

• To ensure the fractions are proper

• To simplify the fractions