First Spanish Reader

7. ANOTHER MATHEMATICAL FIASCO: DIFFERENTIAL CALCULUS

A man buys four handsome donkeys in a fair. He mounts one of them and returns to his house. On the way he counts his donkeys: one, two, and three. He counts them again: one, two, and three. He forgets to count the one he is riding. He arrives at his house and tells his wife: “I have just bought four handsome donkeys in the market place this morning and now I discover only three.” His wife stares at him amazed and replies: “How strange! You see only three while I see five.”