Show:
Round to the nearest 10
Round to the nearest 100
Estimate the sum to the nearest 10
Estimate the sum to the nearest 100
100
23
20
100
890
900
100

43+26=

40+30=70

100

163+237=

200+200=400

200
57
60
200
147
100
200

90+37=

90+40=130

200

54+822=

100+800=900

300
476
480
300
555
600
300

172+109=

170+110= 280

300

445+856=

400+900=1,300

400
923
920
400
451
500
400

205+406=

210+410=620

400

283+26=

300+0=0

500
178
180
500
555
600
500

769+445=

770+450= 1,220

500

998+356=

1,000+400=1,400