KCalc is KDE's scientific calculator.
It provides:
* trigonometric functions, logic operations, and statistical calculations
* easy cut and paste of numbers from/into its display
* a results-stack which lets you conveniently recall previous results
* configurable precision, and number of digits after the period
This package is part of KDE 4, as a component of the KDE 4 utilities module.
See the 'kde' and 'kdeutils' packages for more information.