Basically it is doing all functionality which normal calculator does, addition,substraction division,multiplication and square root.
it has clear butoon "C" which will clear the last charector if some one pressed it mistakly, so that they can update their numbers.
All clear button will reset the calculator.
Divide by zero will not give infinity, instead it will give 0, so that user don't have annoying messages displayed.
NaN messages are also replaced by zero.
User can not enter more than one dot"." So that app crashes has been optimized here.
User can do multiple calculation with this calculator.