LOGO Programming 
Words that Use Numbers
The words we know in LOGO can do something different if you
type different numbers after them. FD 100 draws a line with 100
steps in it, and FD 50 draws a line with only 50 steps in it.
We can make our new words use numbers too. Let's change our
SQUARE word to draw squares of different sizes:
TO SQUARE :SIZE
REPEAT 4 [FD :SIZE RT 90]
END
Now you can tell logo to:
SQUARE 50
or
SQUARE 100
Here's another cool program. What does it do?
REPEAT 100 [SQUARE REPCOUNT RT 10]