Little Johnny's father sees him crying and worriedly asks what's wrong. "Oh," Johnny sniffles. "I lost a nickel."
"There, there, son," his father says kindly. "I'll give you a nice new nickel." He then reaches into his wallet, takes out a nickel, and gives it to Johnny.
Despite his father's kindness, Johnny only cries harder. "Say, what's wrong now, son?" his father asks, very perplexed.
"Now I wish I'd said I lost a quarter!"
Teacher: "What a strange pair of socks Johnny, one of your socks is striped and the other is plain red."
Johnny: "Yes, it is very strange. I have another pair at home exactly the same."
Teacher: "What is a nitrate?"
Little Johnny: "I'm not sure, but it's NOT cheaper than a day rate!"
Teacher: What is the lowest frequency noise that a human can register?
Little Johnny: A mouse.
Teacher: What is the highest frequency noise that a human can register?
Little Johnny: Mariah Carey.