ErnellCalculator is a free calculator application. It has a simple to use interface. Just type the expression that you like to calculate in the calculation area and hit enter. The result will be shown at the desired form (rational, real or both). You can also use the num-pad dialog to enter the expression you want to calculate. The number of decimals shown can easily be adjusted with the "decimal-slider". All calculations, variables, conversions and settings can be saved. Hit print or print preview to print the calculation sheet. Use the Trigonometry-dialog for trigonometry functions or solve triangles with the triangle-solver. Supply the known lengths or angles and the triangle solver will calculate the rest for you. There are a number of useful functions for complex numbers in the Complex dialog. You can define your own variables or constants under in Variable dialog. Variables or constants can also be defined directly in the calculation area. To quickly access variables/constants use the variable-toolbar. Go to the Conversions dialog to make conversions between all kinds of units. There are a Latin a Greek and a "math" keyboard available. Use the CAPS-LK buttons to switch between capital and small letters.