Four colored pencils/crayons/markers and a little bit of glue and you'll have a fun and colorful Pi Day activity that will work for all your students. Your kids will start by coloring each square a different color. The first square can easily be glued inside the circle. The students will have to cut the 2nd square either one or two times depending on where they placed the first square, but it will fit. The 3rd square will take a little more work (cutting & glueing) in order to fit inside the circle...and the 4th square (the one cut into hundredths) will not fit easily.
I have my kids go one little square at a time. They should be able to get 14 of them inside if they are careful...and there you have it... 3.14...Happy Pi Day. :)