15-9=
20+6=
19-10=
97-60+20=
33+20=
57-2=
38+9=
54-8-30=
79-40=
23+6=
13-4+7=
5+45-5=
18+9+7=
30+20-40=
60-30+12=
29+(12+8)=
15-7=
15-2=
42-2=
50+8=
12+5=
18-8=
70+1=
89-80=
14-9=
5+6=
38-8=
49-9=
12+7=
15-8=
20-10=
5+9=
11-2=
20-4=
8+8=
7+9=
14-3=
18-4=
12-6=
9-2=
13-8=
47+53= 420÷70= 100-28.5= 0.03×8= 234- 199=
50×80= 2.7÷0.9= = 1÷ =