Included is a blue print with forms and directions to put together a Pi Day celebration. I coordinated this with the entire 6th grade (12 rooms) and it went very smoothly. I included lesson plans for every subject to do something "Pi Day" related in a cross-curricular manner.
I had students decorate the teacher's doors in a "Pi" theme. This can be done by homeroom or volunteers. During our "advisory" time, each homeroom used different color paper strips (each color represented a digit) and we had a competition to see which homeroom could extend their chain the farthest. We hung the chains from my room.
I purchased a "Pi" shirt and had a competition at the end of the day in the auditorium. The student who could recite the most digits in Pi would win the shirt. (winner was over 120) We capped off the day with a pie eating contest between myself and 3 other students. The other students made signs and cheered for the student from their team. It was a fun day for everyone.