Boy: Who invented numbers?
Girl: THE PRESIDENT. Duh.
Boy: Which president?
Girl: THE president!
Other Boy: I thought it was God.
Girl: Nu-uh!
Other Boy: God invented the president! So if the president invented numbers, GOD invented numbers!
Me: And what identity is that?
All: (general mumblings)
Boy: Ooh! Ooh! Transitive property!
Girl: I knew that.
Me: Good.