subtract
2-1=
1
1+5=
6
1+3-2=
2
7-1=
6
12+30=
42
6-3=
3
2+8=
10
3-1+5=
7
10-10=
0
140+50=
190
90-10=
80
30+20=
50
5+6-3=
8
2+9=
11
122+100=
222
80-50=
30
27+23=
50
8-1+4=
11
12+3=
15
20+133=
153
100-60=
40
37+40=
77
12+16-10=
18
17-5=
12
128+177=
300