Estimating Sums and Differences in Fun Math Challenges

Lily has 25 apples. She gives 7 apples to her friend and then buys 15 more. How many apples does she have now? Estimate the total before calculating.

• 20

• 33

• 25

• 40

Tags

CCSS.1.OA.A.1

Tom has 40 marbles. He loses 12 marbles and then finds 8 more. How many marbles does he have now? Check your answer by estimating first.

• 28

• 32

• 44

• 36

Tags

CCSS.3.OA.D.8

A farmer has 50 chickens. He sells 20 and then buys 10 more. How many chickens does he have now? Estimate the difference and sum.

• 30

• 25

• 40

• 60

Tags

CCSS.1.OA.A.1

Sarah read 15 books in January and 20 books in February. If she gives away 10 books, how many books does she have left? Estimate before solving.

• 30

• 20

• 15

• 25

Tags

CCSS.2.OA.A.1

In a classroom, there are 30 students. If 5 students leave and 10 new students join, how many students are in the classroom now? Check your answer by estimating the changes.

• 25

• 30

• 40

• 35

A toy store had 100 toys. They sold 45 toys and then received a shipment of 30 new toys. How many toys are in the store now? Estimate the total before calculating.

• 100

• 90

• 70

• 85

Mark has 60 stickers. He gives 15 stickers to his sister and then buys 25 more. How many stickers does he have now? Check your answer for accuracy.

• 70

• 80

• 50

• 65

Tags

CCSS.2.NBT.B.6

Emma collected 80 seashells. She gave 25 to her friend and found 10 more on the beach. How many seashells does she have now? Estimate the total before calculating.

• 55

• 75

• 85

• 65

A library has 200 books. If 50 books are checked out and 30 new books are added, how many books are in the library now? Check your answer by estimating first.

• 200

• 170

• 150

• 180

Tags

CCSS.2.NBT.B.7

Jake has 90 toy cars. He donates 30 cars and then buys 20 more. How many toy cars does he have now? Estimate the difference and sum.

• 60

• 100

• 80

• 70