I’m not trying to be rude, but I’m not sure how that’s supposed to be a logo?
Does it look clean? Well, I suppose so. But it’s a calculator, not a logo. Imagine that being printed, at around maybe 50px x 50px. You would just see a square.
If you wanted to keep with a calculator theme, perhaps you could just use the + key. Something like…
Obviously mine is not good, but you get the idea.