KCalc is a calculator which offers many more mathematical functions than meet the eye on a first glance. Please study the section on keyboard accelerators and modes in the handbook to learn more about the many functions available.
The latest stable release is version 2.10, included in KDE Applications 4.8. KCalc is a free and open source software, available for Linux and similar operating systems
In addition to the usual functionality offered by most scientific calculators, KCalc offers a number of features, which I think are worthwhile pointing out:
Calc provides trigonometric functions, logic operations, and it is able to do statistical calculations.
Calc allows you to cut and paste numbers from/into its display.
Calc features a results-stack which lets you conveniently recall previous results.
ou can configure KCalc s display colors and font.
ou can configure KCalc s precision and the number of digits after the period.
KCalc offers a great number of useful key-bindings, which make using KCalc without using a pointing device easy.
Hint: pressing (and holding) the Ctrl-key, displays on every button, the corresponding key-binding.