16-7= 42+8= 27+30= 30+60= 12-( )=7
6+27= 50-5= 8+18= 31+9= ( )-6=9
35-5= 64-40= 28-3= 34-6= 18-9+8=
25+4= 47+7= 23-9= 8+45= 24-20+73=