GrandmaK, I'm delighted to have been able to help you "see" the problem, LOL! And I thank you and Peggi for your compliments.
Long ago I actually developed a teaching tool for showing this principal in my classes.... by making a 4 patch of rail fence blocks, four different sizes, just by increasing the cuts 1/4"-1/2" at a time. That visual usually produces quite an "aha" moment.
Guess it shows, I LOVE to teach!
Jan in VA