Dear Principal Skinner,
I think it's an interesting project idea to have each 4th grade class develop their own identity. Like flags, secret codes, and secret claps. I understand this is a 2 week project, this week with students developing their own "countries" and next week sharing their ideas with other classes.
But I think you could have ended your talk better than with the line "Next week you'll visit other classrooms to share your clap with them."
And you wondered why the teachers in back began snickering.