Show:
Subtraction
Find the unknown
Rounding
Estimation
Addition
100

321-116 = 

205

100

63 + w = 75 

W=

w=12

100

Round to the nearest 10.

267

270

100
Estimate by rounding to the nearest 10. 75 + 12
What is 90?
100
192 + 464
What is 656?
200

614-322=

292

200

U + 249 = 312

U  = 63

200

Round to the nearest 100

648

650

200

Which 2 numbers have a sum the closest to 700?

560

300

270

442

270 & 442


270 + 440 = 710

300+400=700

200
387 + 251
What is 638?
300

256-182=

74

300

____ + 16 = 3 x 10 

14

300

Round to the nearest 10

671

670

300

Estimate by rounding to the nearest hundred to find the sum. 305 + 853

What is 1,200?

300
834 + 486
What is 1320?
400

127 - 89 =

38

400

 5 x 12 = ___ + 25

35

400

Round to the nearest 10 and 100


245

Nearest 100: 200

Nearest 10: 250

400

True or False

329 - 113 = 330 - 112

False 

Constant difference says you need to do the same to both sides they added 1 to 329 and subtracted 1 from 113

400

345 + 656

1,001

500

500 - 214

286

500

___ + 22 = 32 +58

68

500

List 5 numbers that when rounded to the nearest 10 would round to 360

355,356,357,358,359,360,361,362,363,364

500

True or false

329+113 = 330+112

TRUE

You can move some from one of the addens to create a friendly number with the other

500

895 + 147

1,042