The Default PlayBook Calculator is more than just a Calculator
I use the calculator quite often on my BlackBerry PlayBook and for those that still use theirs, I am amazed that many did not know they could swipe down to get to other features.
The calculator when you swipe down lets you choose a Scientific Calculator, Unit Converter and a Tip Calculator.
The calculator is great but having the other features in worth quite a bit. Try and buy a good scientific calculator, no need when you have a PlayBook near by.