Used SigmaConsole for Windows?
Developer’s Description
By Hamady
SigmaConsole is an advanced mathematical console. It supports the most common and useful functions. It's easy to use: to evaluate an expression, simply write it, using operators (+ - * / ^), parenthesis and mathematical functions and press ENTER. You can also use the numeric keypad to enter numbers and operators. You can set variables (with any non-reserved name), using fundamental constants.