num1,operation,num2,Output,flag 1,add,1,2,other 10,multiply,124,1240,other 2,add,2,4,off by one ,add,,,other ,add,,,off by one ,add,,,wrong sign ,add,,,wrong sign 1,multiply,2,2,off by one 1,multiply,2,2,off by one ,add,,,wrong sign 6,divide,8,0.75,off by one 88,multiply,88,7744,other ,add,,,wrong sign ,add,,,wrong sign ,add,,,off by one