Thank you for your answer. That's pretty much what we've been doing - I'll hold the t-square steady while he lines up the triangle and draws the line. I really appreciate YOU saying that it is important to use the tools correctly though - it is somehow more "official" coming from the "people who wrote the book" - now my son knows that it is important to stick with using the t-square the proper way, even if we don't see the reason for it now. Thanks again - Amy