56+15= 20+70= 57-20= 11-4=
90-40= 52+8= 73-3= 29+30=
16-8= 8+60= 90+5= 28-8=
33+9= 90+10= 98-8= 74+6=
40+20= 98-90= 37+50= 59-7=
29-7= 17-4= 100-30= 7+34=