Alternate Calculator is a freeware calculator that has different numbers and currency conversions.
The interface looks like any other calculator, and the window can be resized to a rectangle or full screen, taking up as much or as little space as you like. You can also change the colors.
Alternate Calculator has two primary features that it is designed around. The first is currency translations, with eleven currencies currently supported. We assume this might change over time. The other primary feature is the conversion between different number formats. These are found at the top and are decimal, hexadecimal, binary, and customer-defined.
One missing feature is the numerical keypad. Those are the numbers to the bottom right of your keyboard. You need to use the numbers across the top of your keyboard.
All told, Alternate Calculator is a calculator for anyone, especially if you need numbers and currency conversions.
Free42 HP-42S Calculator Simulator is an Open Source recreation of the HP-42S Scientific Programmable Calculator and HP-82240 Printer. Plus42 is also available.