21+50= 70-11= 78-17= 31+32=
    26+40= 6×5= 4×4= 25+25=
    95-20= 36+40= 83-83= 4×2=
    75-40= 90-80= 50+37= 43+42=
    27-11= 37-3= 8+17= 55+45=
    58+2= 46-14= 3×3= 45+15=
    90-29= 65+9= 43+37= 1×1=
    30+27= 7+36= 8+12= 10+22=
    37-26= 72-7= 5+43= 38+22=
    24-24= 4×3= 2×2= 60+35=
    33-7= 49+11= 3×2= 6×2=
    98+2= 12-7= 49+51= 38+12=
    93-80= 96-8= 67+7= 27+35=
    5×4= 4×6= 4+2= 40-2=
    3×3+2= 4×5-1= 6×6-7= 4×3+4=