Are you sure you're in third grade?

Me: (sternly) "Do you plan on shooting spitballs in the cafeteria in the future?"
Student: "Three words: not gonna do it."
Me: (totally losing my cool and cracking up) "Okay..."
Other Student: "Man, I told you it was four words!"

When reviewing what they learned about American Indians in second grade

"Ms. Kirch, back when the American Indians were alive... did human beings exist yet?"