A lot of care and attention has been paid to small details often overlooked on similar products. Proficiency is easy to use, and has a comprehensive, but uncluttered display area. As mentioned above, Proficiency is an RPN calculator. The other popular notation is Algebraic. Proficiency always displays the RPN Stack, letting you see the intermediate processing.
All functions are available either way.
Tabbed pages organize functions into logical groups. You can jump between tabs as necessary to accomplish your calculations. If you are looking for a financial product to do standard, business, or scientific calculations, you may not have to look much further than Proficiency. Proficiency's Conversion screen is shown above. The 480 pixel wide display on top, the 640 pixel wide display on the bottom.