Using Benchmarks
Use benchmarks to estimate the sum or difference.
1 5/12 - 2/3
1
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
Find the sum or difference.
3 5/6 - 1 7/12
2 3/12
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
Find the difference.
5 - 2/3
4 1/3
Use benchmarks to estimate the sum or difference.
7/10 + 7/8
1 1/2
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
Find the sum or difference.
4 1/2 - 2 1/3
2 1/6
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
Find the sum.
6 2/3 + 3 5/6
10 1/2
Use the benchmark to estimate the sum.
3/8 + 1 4/5
2 1/2
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
Find the sum or difference.
5 1/3 + 3 3/7
8 16/21
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
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
Use the benchmark to estimate the sum or difference.
3 2/10 + 1 1/6
4
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
Find the sum or difference.
2 4/9 + 1 1/4
3 25/36
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
A pitcher contains 8 1/2 cups of lemonade. After pouring out 4 3/4 cups, how much lemonade is left?
3 3/4
Use the benchmark to estimate the sum or difference.
1 4/5 + 1 7/8
4
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.
3 1/5 + 2 1/4
5 9/20
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
Find the difference.
10 - 7/8
9 1/8