Show:
Estimates
Standard Algorithm
Double and Halving
Extending the 5s
Extending the 9s
100

Estimate: 

267 + 378

About 650

100

345 + 278 =

623

100

Double 350

700

100

44 x 5=

220

100

9 x 15 =

135

200

Estimate:

744 + 566

About 1,310

200

3,904 + 245=

4,149

200

Halve 240

120

200

16 x 5=

80

200

29 x 5 =

145

300
Estimate:


1,078 + 1,957

About 3,100

300

2,300 + 9,892=

12,192

300

Double 870

1,740

300

32 x 5 =

160

300

69 x 3 =

207

400

What Place Value Amount should you estimate to in the following equation?

234 + 237

Tens Place

400

470 + 345 + 210=

1,025

400

Halve 230

115

400

35 x 5 =

175

400

19 x 4

76

500

What Place Value Amount should you estimate to in the following equation?

1,456 + 7,766

Hundreds Place

500

23,457 + 2,255 + 897=

26,509

500

Double 440

880

500

48 x 5=

240

500

9 x 27=

243