Adding and Subtracting Fractions with Unlike Denominators

Mr. Leatherwood introduces the concept of adding and subtracting fractions with unlike denominators. He explains the importance of having the same denominator and demonstrates using models and numerical methods. The video covers finding the least common multiple to adjust denominators and provides examples of both addition and subtraction of fractions.

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

• To simplify the process of addition or subtraction

• To make the fractions look similar

• To ensure the fractions are equivalent

• To avoid making the teacher sad

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

• Add the numerators directly

• Find the least common multiple of the denominators

• Subtract the smaller denominator from the larger one

• Convert the fractions to decimals

In the example of 4/10 + 3/5, what is the least common multiple of the denominators?

• 5

• 10

• 15

• 20

After converting 3/5 to a fraction with a denominator of 10, what is the new fraction?

• 3/10

• 6/10

• 12/10

• 9/10

What is the result of adding 4/10 and 6/10?

• 1/10

• 10/10

• 10/20

• 1

In the example of 3/7 + 2/21, what is the least common multiple of the denominators?

• 28

• 14

• 21

• 7

What is the new fraction when 3/7 is converted to have a denominator of 21?

• 12/21

• 3/21

• 6/21

• 9/21

What is the result of adding 9/21 and 2/21?

• 10/21

• 12/21

• 11/21

• 9/21

In the example of 3/4 - 5/12, what is the least common multiple of the denominators?

• 12

• 8

• 16

• 4

What is the simplified result of subtracting 5/12 from 9/12?

• 2/3

• 1/2

• 1/3

• 1/4