Daily UI #004 Calculator

Hi Dribble! Here's Day 4 of Daily UI Challenge.

I made this a couple of weeks ago, but I never liked it enough to actually post it. I came across it right now, and decided to give it a shot.

This was fun because i study maths at Uni ( a lot ), so I tried to make something that would be useful for me, as well.

Hope you like it. Any Feedback is helpful.

Thank you!