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.