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