Rounding
Properties of addition
Estimate the Answer
Find the Sum
Find the Difference
100

47 rounded to the nearest ten

50

100

Which property says that

6+3=9

3+6=9

Commutative Property of Addition
100

Estimate the answer:

47+23=

50+20=70

100

234+155

389

100

555-145

410

200

323 rounded to the nearest hundred

300

200

Which property says that

157+0=157

Identity Property of addition

200

Estimate the answer:

64-37=

60-40=30

200

340+239

579

200

487-187

300

300

453 rounded to the nearest hundred

500

300

Which property allows the following to be true?

(5+3)+6= 5+(3+6)

Associative property of addition
300

Estimate the answer:

523+274=

500+300= 800

520+270=790

300

465+235

700

300

519-290

229

400

607 rounded to the nearest ten

610

400

The _______ property of addition states that any number plus 0 results in the number itself. 

Identity 

400

Estimate the answer:

678-431=

700-400=300

680-430=250

400

378+456

834

400

674-362

312

500

809 rounded to the nearest hundred

800

500

Ms. Emily wants to check her answer to the problem

56+23=79

What problem would she write to check her answer?

79-23=56

OR

79-56=23

500

Estimate the answer:

523-261=

500-300=200

520-260=260


500

571+432

1003

500

424-189

235