13-7= 15+9= 30+50= 60-30=
6+44= 67-7= 53-30= 38+40=
13-4= 25+8= 44-7= 17-9=
20+35= 97-70= 30+50= 53+9=
48-30= 80-5=
78-42= 55+20= 57-50= 66-5= 60+30=
36+23= 6+32= 20+46= 40-9= 98-37=
12-4 = 17-9= 18-8 = 20+60 = 50+5 =
40+22 = 60+38 = 70-50 = 89-6= 91-40 =