Adding & Subtracting Fractions with Unlike Denominators_4thGrade_JM

Adding Fractions with Unlike Denominators

100

1/4 + 2/3 = 

11/12

200

1/3 + 3/9

*Write your answer in simplest form.

6/9 then simplify to 2/3

300

3/4 + 1/9 =

31/36

400

4/9 + 1/6 =

*write your answer in simplest form

11/18

500

1/4 + 3/7 =

19/28

Subtracting Fractions with Unlike Denominators

100

4/5 - 1/3 =

7/15

200

4/3 - 2/7 =

22/21 

300

3/4 - 1/9 =

23/36

400

6/7 - 1/2 =

5/14

500

9/10 - 1/4 =

*Write your answer in simplest form 

13/20

Least Common Denominator

100

1/2 and 3/5

LCD: 10

200

5/12 and 2/9

LCD: 36

300

1/7 and 4/8

LCD: 56

400

9/10 and 5/6

LCD: 30

500

1/4 and 2/3

LCD: 12

Understanding Fractions

100

If the denominators are the same for two fractions, do we have to find the least common denominator (LCD)?

No, we can add or subtract the fractions as is.

200

What is the first thing you do when you are adding or subtracting fractions with unlike denominators?

List the multiples of the two denominators in order to find the LCD.

300

What do we call fractions that represent the same value, but have different numerators and denominators?

Equivalent Fractions

400

What are unlike fractions? 

Fractions with different denominators. 

500

Do you have to find the least common denominator to add or subtract unlike fractions?

No, you need a like denominator, but it doesn't have to be the LEAST common denominator. 

Factors Review

100

List the factors of 18

1, 2, 3, 6, 9, 18

200

List the factors of 30 

1, 2, 3, 5, 6, 10, 15, 30

300

List the factors of 21 

1, 3, 7, 21

400

List the factors of 9 

1, 3, 9

500

List the factors of 8

1, 2, 4, 8