Daily UI 004: Calculator

Today's #dailyui challenge: Calculator

There seems to be a plethora of traditional calculators out there, even just as concepts. So I went with a tip/gratuity calculator and tried to keep it as simple as possible.

Real pixels in the attachment. I realized that for each of these Daily UIs I've done I've started out by sketching stuff out. So I also attached my quick-n-dirty™ sketches that I did to flesh out this idea. I'm old school, I guess; can't start on design without a sketch. :)

Also, this is the first time I've ever created a UI for an app; be gentle. :)