CalcFire is not a calculator itself, it is rather a shortcut to the Windows calculator. Its objective is to facilitate access to the Windows calculator making its use more convenient, fast and functional.
CalcFire is installed as an icon on the same Windows taskbar. It can be activated automatically in two ways: By clicking on that icon or by pressing the NumLock key on your keyboard.
So thanks to CalcFire you always have the calculator, both the standard and the scientific one, at hand for any operation you have to do, but discreetly minimized so as not to bother you.
You can free download CalcFire 32, 64 bit and safe install the latest trial or new full version for Windows 10 from the official site.