Chalkboard is an unconventional, yet intuitive, "calculator." It allows you to describe equations the way you would with traditional paper and pencil. Only now, the number crunching is done for you, at the press of a button.
Chalkboard has many features that are both highly convenient and functional. Instead of having to memorize numbers, all you have to do is assign them to a variable for later use. Or perhaps you have a complex equation that's always hard to remember? Now, just create a function for it and you'll never have to worry about it again.
On the technical side, Chalkboard is designed to emulate the functionality of a programming language, while maintaining a syntax with the potential simplicity of a traditional calculator. Along with functions and variables, Chalkboard also supports for-loops, lists/arrays, strings, complex numbers and graphing. Chalkboard is also fully extensible -- you can add an unlimited number of functions and variables and keep them for later use.