Very nice program. The best of its kind, and freeware too. If you feel constrained when using Windows build-in calculator and want to make fast calculations when studying, then this is the best calculator for you. Very intuitive, easy to use, flexible. You can create your own variables, functions, and save them for later use. Has many build-in functions and constants from many areas of study (math, physics, etc). AT LEAST TRY IT!