When you start the screen, a simple cubic equation is written for you to solve. What's simple about it? Well, the coefficient of the cubed term is 1, and there is one solution which is an integer between -5 and +5.
At the first step you have to find this integer root, by trying different values of A (press the 'A+' or 'A-' button). Notice that finding this root involves using the Factor Theorem.

Once you've done this you move on to further steps in the calculation, which is mostly done for you. After you've got your other solutions (if they exist), a graph of the function is drawn, so that you can see how the solutions relate to the graph. The purpose of this program is to help you understand the process of finding solutions to this type of cubic equation. Enjoy and learn!