HiDigit is a scientific calculator with extended capabilities for Windows . This essential and powerful program works best for math, algebra, calculus, geometry, physics and engineering students and even their teachers. One of the advantages of this calculator is a simple input format even for the most complicated scientific formulas. For example, you can enter 10pi instead of ”10*pi”. For complex numbers, you can use the following format - ”1+2i”. For percentages - ”number + %”. The other important feature of HiDigit is its high precision - up to 15 decimals for scientific calculations. The program features an impressive number of built-in formulas, functions, constants and coefficients. Importantly, the users can customize all of them or add their own variables. Also, the history of all actions is kept, so the users can come back and undo/redo any action at any time. Being a serious calculating software, it is extremely simple in use. No special computer skills or knowledge are required. The interface is straightforward and very easy to navigate through. The compact size of the calculator does not hinder the performance. To the contrary, the program can even be used by the multiple users simultaneously. (Source: http://mathres.kevius.com/software.htm)