Island advanced calculator

Island Advanced Calculator can solve whole expression at once. It respects all mathematics rules and priorities of operators, brackets and real numbers.

It also checks if expression is entered correctly.
Excepting standard operations there are also custom powers and roots (not only 2th), factorial and sinus/cosinus. Values of last 2 are in degrees.
Program size is very small and it is easy to use. It's extremely useful in school because you don't have to waster your time with partial results.