20+43= 59-8= 40+60= 15-8= 46-6=
13+50= 68-40= 18-9= 78+20= 37-30=
14-5= 48-8= 56-4= 11-2= 28-3=
20-10= 21+7= 16-7= 8+32= 12-4=