Super prática! Eu realmente gosto da calculadora !

I would give it 5 stars if you could use parenthesis when calculating.
Even a simple calculator needs it.

Trying adding other modes like programming, scientific advanced etc.

At last, one calculator add on that works!!!
Is it possible for you to add a history of calculations and that can be viewed even after a restart of Firefox?!? Also with that if possible to take advantage of past calculations and re-use them...