KCalc

KCalc is a scientific software calculator integrated with the KDE Gear.

Functions
KCalc includes trigonometric functions, logic operations, saved previous results, copy and paste, a configure UI, and statistical computations. The history function uses a stack method. KCalc also supports boolean operations.

KCalc does not support graphing.

Since version 2 (included in KDE 3.5) KCalc offers arbitrary precision.