JS Calculator Feedback and Bug Hunt

Hey guys and gals,

I’ve nearly completed this Calculator Project, wondering if I could get some criticisms on it?

Also, there are a couple of bugs that I’ve had trouble routing out.

*if the user hits one of the operation buttons in a row, it outputs NaN

*if the user doesn’t clear the last answer before calculating a whole new problem the answers get added in a very weird way: (1) 8 + 8 = 6 (2) 8 + 8 = 176

I see what the logic is behind that last one but, I’m not sure how to stop it from happening.

Thanks in advance,