You might like to make the number after theWAIT command larger so that you have time to see what is happening. Alternatively, many LOGO programmes allow you to "Step" through a procedure and see the results of each line of code.

There are two variables - try fixing one and varying the other.

It might also be helpful to imagine the variable as a box into which you put a number and to record on a piece of paper the number in the variable boxes after each iteration of the procedure.