I like it! —and had to think about it too. One calls for another --from my math teacher repertoire:
So there was this brilliant horse that his owner liked to show off to his friends. “Ask him anything! And he’ll tap out the answer with his hooves, the owner bragged.” Sure enough, when asked how many days are in a week, the horse tapped 7 times. And the horse astoundingly answered many other questions correctly too, that is, until somebody asked him this math question: “What are the coordinates of this point right here along the x-axis?” At that moment the horse fell down dead.
Moral: Never put Descartes before the horse.