Show:
Round to the nearest ten
Round to the nearest hundred
Ballpark estimate the sum
Ballpark estimate the difference
10
23
20
10
890
900
10
43+26=
40+30=70 43+26=69
10
63-37=
60-40=20 63-37=26
20
57
60
20
147
100
20
90+37=
90+40=130 90+37=127
20
54-22=
50-20=30 54-22=32
30
476
480
30
555
600
30
172+109=
170+110= 280 172+109=281
30
145-56=
150-60=90 145-56=89
40
923
920
40
451
500
40
205+406
200+400=600 205+406= 611
40
283-256=
280-260= 20 283-256= 27
50
178
180
50
555
600
50
769+445=
800+400=1,200 769+445=1,214
50
778-356=
780-360=420 778-356=422