50+2090-8 36+1955 4353-4
7+256+24 36+2450 78-868+2 82+790
18+3020+28 67+2080+6 50-540+5
46-20= 78+20= 69-20= 17+6= 7+35=
86-20= 58-9= 97-20= 68+5= 32+20=