This calculator has two modes a simple and advanced mode. The choice is yours, and you can switch between the two modes easily. In Simple mode it has the just the 4 basic math functions, using the navigation key to select the function. In advanced mode, the navigation key switches between different input modes. The first mode is the numeric mode where the keys enter the corresponding numbers. The next mode is scientific, which is used for the basic math functions and scientific functions. The third mode is trigonomic mode where you can access the trigonomic functions. This new version is vastly improved from the previous. Please enter some reviews or let me know what you like and don't like about it. Let me know of any bugs also, as there is no one else testing it for me. Best of all, it is still free.