A fourth-grade teacher was giving her pupils a lesson on logic.
"Here is the situation," she said. "A man is standing up in a boat in the middle of a river, fishing. He loses his balance, falls in, and begins splashing and yelling for help.
His wife hears the commotion, knows that he can't swim, and runs down to the bank. Why do you think she ran to the bank?"
A girl raised her hand and asked, "To draw out all of his savings?"