The first part of that was very popular when I was teaching kat. It didn't use lumber but something equally simple in word problems. At that time however it was meant to point out (as it still does along with the Enron Debacle) where our educational system has gone. Very funny in this application but still an equal indictment of the problems in education.

Education: The inculcation of the incomprehensible into the indifferent by the incompetent to the unconscious.

Spaw