Pi Day usually falls when our end of quarter testing is wrapping up so it's a perfect way to close the quarter. It also makes my classroom super cute for 4th quarter!
I put the first 1000 digits of Pi on the SmartBoard for them to mark off as the chain is being made. Each digit is color-coded and I have the strips taped to the board for them to reference. We sit in a circle, of course, and just paper chain away! Each class always has a couple of leaders that step up to organize and make it happen.
I hang it up and add little Pi die cuts to the loopty loops and voila! A perfect end to a math nerd day!