The teacher asked little Johnny, “Johnny, if your father borrowed $200 and promised to pay it back at $10 each week, how much would he owe at the end of the week?”

Little Johnny had a think about it and replied, “$200.”

The teacher, getting frustrated, said, “You don’t know your arithmetic very well, do you, Johnny?”

With a grin on his face, little Johnny replied, “Maybe not, but I do know my Dad.”