Lionel

Hi Everyone. This is my first attempt at the On Screen Calculator. My commits are not small, and I apologize for that Zee. The only functionality that I see that throws an error is clicking on operators more than once before clicking on another number. I don't think some of the edge cases I addressed were necessary, but since I'm building these applications for my portfolio I'd like it to be fairly clean.

Thank you for your help.
This  is the same code as 37; extract to a function that takes a `resultingNumber` argument.