12+3*4+5-6+789=812
1*2*3*4+5-6+789=812
12-3+4*5-6+789=812
1/2+3/4*5*6+789=812
1/2+3*45/6+789=812
123+4*5+678-9=812
12+3*45*6+7-8-9=812
123*4+56*7-8*9=812