Properties and Strategies to Add and Subtract

1 + (8+3) = (1 + 8) + 3

• Associative

• Commutative

• Identity

2 + 8 = 8 + 2

• Associative 

• Commutative

• Identity

What number fills in the blank?
5 + (7 + 6) = (5 + ___) + 6

• 8

• 6

• 5

• 7

Ms. Palmer drove 278 miles on Tuesday and 342 miles on Wednesday. How many miles did she drive in all?

• 600

• 602

• 620

• 700

679

+56

• 61215

• 635

• 4635

• 345

• 735

Joseph has eight stamps. His parents gave him three more stamps. How many stamps does Joseph have now?

• 11 stamps

• 12 stamps

• 13 stamps

• 5 stamps

Andrew has 10 Hot Wheels cars.  He got some for his birthday.  Now, he has 17 cars.  How many cars did he get for his birthday?

• 7

• 17

• 27

• 100

Estimate the difference .

• 90

  -50

  40

• 90

  -40

  50

• 80

  -50

  30

Estimate the difference.

• 800

  -700

  100

• 700

  -600

  100

• 700

  -700

  000

Estimate the difference.

• 80

  -30

  50

• 90

  -30

  60

• 90

  -40

  50