Using Benchmark Fractions to Estimate
What is a good estimate for 5/8 - 1/9?
About 1/2
1/5 + 3/10
5/10, 1/2, etc.
1/2 - 1/4
1/4
4 4/5 - 2 1/2
2 3/10
Grayson mixes 1/2 pound of strawberries with 1/4 pound of blueberries. What is the total weight of berries Grayson has?
3/4 pounds
What is a good estimate for 1/3 + 1/6?
About 1/2
1/2 + 1/4
3/4
1/2 - 1/8
3/8
2 5/6 - 1 1/3 = ?
1 3/6, or 1 1/2
Nathaniel and Rachel are reading a book for a report. Nathaniel reads 3/8 of the book. Rachel reads 1/2 of the book. How much more of the book does Rachel read than Nathaniel?
1/8 of the book
What is a good estimate for 4/5 + 11/12?
About 2
1/2 + 1/3
5/6
5/12 - 1/3
1/12
4 1/2 - 3 11/12 = ?
7/12
Elizabeth walks 1 1/4 miles to her friend's house. Then they walk 1 7/10 miles to get to the park. How far does Elizabeth walk in all?
2 19/20 miles
Cecily read for for 11/12 of an hour yesterday and and 7/8 of an hour today. For about how long did Cecily read in the two days?
A. Less than 1 hour
B. Between 1 hour and 1 1/2 hours
C. Between 1 1/2 hours and 2 hours
D. More than 2 hours
C.
1/6 + 2/9
7/18, 14/36, 21/54, etc.
3/5 - 1/2
1/10
4 1/2 + 3 11/12 = ?
8 5/12
Cynthia practices the piano for 2 3/8 hours on Friday and for 3 1/4 hours on Saturday. How much longer does Cynthia practice on the piano on Saturday than on Friday?
7/8 hour
Jackie's thermos contains 11/12 cup of soup. After a walk, she eats 5/8 of the cup. Which best describes how much soup is left in the thermos?
A. almost none
B. a little less than 1/2 cup
C. about 1 cup
D. a little more than 1/2 cup
B.
5/12 + 3/8
19/24, 38/48, 76/96, etc.
4/5 - 3/4
1/20
3 3/10 - 1 3/5 = ?
1 7/10
Don jumped a distance of 7 1/3 feet. His younger brother jumped a distance of 4 1/2 and then jumped 3 11/12 feet. Who jumped farther? How much farther?
Don's younger brother jumped farther by 1 1/12 feet.