I'm not sure I understand this comment--it doesn't seem to match what the below code is doing. (granted as i'm reading this i'm not sure how everything comes together yet, so maybe I'm just confused)

I also think it should be fine to type a `+` in front of the leading term since that's the case everywhere else (it appears you're making an assumption that you should never be allowed to do that?). For example in addition_1, if it asks 8+6, you can type `+14`.