Add and Subtract Fractions and Mixed Numbers with Unlike Denominators

Using Benchmarks

100

Use benchmarks to estimate the sum or difference.

1 5/12 - 2/3

1

200

Use benchmarks to estimate the sum or difference.

7/10 + 7/8

1 1/2

300

Use the benchmark to estimate the sum.

3/8 + 1 4/5

2 1/2

400

Use the benchmark to estimate the sum or difference.

3 2/10 + 1 1/6

4

500

Use the benchmark to estimate the sum or difference.

1 4/5 + 1 7/8

4

Using the Common Denominator

100

Write the expression using fractions with a common denominator. Then find the sum or difference.

3/4 - 1/3

9/12 - 4/12; 5/12

200

Write the expression using fractions with a common denominator. Then find the sum or difference.

2/5 + 1/2

4/10 + 5/10; 9/10

300

Write the expression using fractions with a common denominator. Then find the sum or difference.

3/8 + 1/6

9/24 + 4/24; 13/24

400

Write the expression using fractions with a common denominator. Then find the sum or difference.

3/4 - 7/12

9/12 - 7/12 ; 2/12

500

Write the expression using fractions with a common denominator. Then find the sum or difference.

1/6 + 3/9

3/18 + 6/18 ; 9/18

Find the Sum or Difference

100

Find the sum or difference.

3 5/6 - 1 7/12

2 3/12

200

Find the sum or difference.

4 1/2 - 2 1/3

2 1/6

300

Find the sum or difference.

5 1/3 + 3 3/7

8 16/21

400

Find the sum or difference.

2 4/9 + 1 1/4

3 25/36

500

Find the sum or difference.

3 1/5 + 2 1/4

5 9/20

Word Problems

100

Mrs. Young stores flour in a jar. She buys 2 7/8 pounds of flour and puts it in the jar. Now the jar holds 4 1/2 pounds of flour. How much flour was in the jar before Mrs. Young's purchase?

1 5/8 pounds

200

A beaker holds 3 9/10 liters of water. A bowl holds 2 1/2 liters more water than the beaker. How much water is in the bowl?

6 4/10 Liters

300

Miss Wissler buys a bird feeder that can hold 3 1/2 pounds of sunflower seeds. She has 1 9/16 pounds of sunflower seeds. How many more pounds of sunflower seeds does she need to fill the feeder?

1  15/16 more pounds

400

Samantha had 6 1/2 yards of fabric. She used 2 3/4 yards to make a dress. How much fabric does she have left?

3 3/4 yards

500

A fish tank holds 8 5/8 gallons of water when full. Currently, it contains only 3 1/2 gallons. How much more water does it need to be full?

5 1/8 gallons

Mix of Problems

100

Find the difference.

5 - 2/3

4 1/3

200

Find the sum.

6 2/3 + 3 5/6

10 1/2

300

Ben walked 3 2/5 of miles in the morning and 1 3/5 miles in the afternoon. How many miles did he walk in total?

5 miles

400

A pitcher contains 8 1/2 cups of lemonade. After pouring out 4 3/4 cups, how much lemonade is left?

3 3/4

500

Find the difference.

10 - 7/8

9 1/8