Pi is such a magic number and March 14 (3/14) is Pi Day! Coincidentally, it is also Albert Einstein’s birthday. Although it is usually represented as 3.14 for basic geometry calculations, Pi has an infinite string of numbers, with no repeating pattern, after the decimal point.
Have children color in the symbol for pi on this Pi Day printable magic hat(click for .pdf), cut out the hat, and glue onto a construction paper headband.
Measure the circumference of their heads (using the construction paper headbands) and confirm that the circumference really is the diameter multiplied by pi!
We also read Sir Cumference and the Dragon of Pi (A Math Adventure).
And, over at Bedtime Math, we made super-simple mini “apple pi.”