Natural Calculator is a unique, powerful, and simple program for solving various mathematical tasks. Unlike any other such programs, Natural Calculator does calculations the same way you do them on paper. That’s because it uses conventional graphical mathematics syntax instead of string. Because Natural Calculator is an all-in-one solution to everything from everyday arithmetic to engineering solving, different people can use it for various jobs. * Natural Calculator's on-screen interface is a blank on which you can enter text or mathematics expressions in handy graph view. The expressions are output the same as on paper. * Results may have any predetermined number of digits and precision. You can define them for the whole document or for a separate expression. * Computations can be performed with the following numbers: scientific, integer, rational, complex. * Angular measure may be defined for a separate number, an expression result, or the whole document. * There are built-in constants and functions. * User variables and functions are useful. You can define them easily and use them in your computations. You can redefine built-in constants and functions also. * Natural Calculator uses units of measurement. There are built-in and user units. You can define your own units or redefine existing ones. You can convert units within one unit system or from one to another system. * The program uses handy automatic recompute on user input. Change a number or the value of a parameter and see what happens to your expressions and their results. * There are two computation window types: standard multistring document and one-formula window. * There is integration with mathematical programs that run formulas in string view through the clipboard. * Natural Calculator uses include documents to use their variables, units, and functions. * There is syntax highlight. * Complete documentation is available.