① ②
83+17= 840-440= 150×6= 599-203≈
12×7= 103×2= 0×199= 903×9≈
1.2+8.8=
6.07+1.9=
0.2-0.09=
0.37+0.17=
1.2+3.6=
8.5+2.5=
1.9-0.17=
0.75+0.4=
3.4-1.4=
0.65+3.5=
20+0.78=
0.68+0.42=
0.8-0.5=
4.8+4.2=
7.82-7.2=
0.24+0.36=
5.7-3=
2+9.1=
7.1+8=
4.9-1.7=
0.48+0.52=
6.34-0.64=
1.34+0.8=
8.1-5.1=
5-0.26=
2-0.75=
0.78-0.24=
4.3-4.3=
8.7+0.03=
0.8+0.18=