Look at the Keyboard section of the Reference.
For more complex input, you have to look at the GUI libraries.

Thanks, I already had done that...thus the question.   What I want to be able to do is declare multiple variables, say for grades...then get values into those variables through the keyboard.  I am not interested in trying to monitor keyboard presses to change a sketch, but rather do standard entry into variables...teaching the basics of programming

Again, see the GUI Libraries for such usage.