As I learned C#, I tried to bring the calculator to life through WindowsForm to make it a usable and functional application. Of course, it has many shortcomings, for example, I couldn't give number format to the textbox (whenever I try to give it with parse, the decimal separator disappears :S) or I don't know how to make the application resizable correctly. But at least, I think I managed to make a simple calculator that works properly :).