Celebrate **π** in your school and in your math class with activities that demonstrate how π was derived; visually show why π makes sense; show a surprising place where π is used; increase students ability to measure and long divide; applauds the talent of people who can memorize large strings of numbers; and lets students just have fun.

**PiDay-ClassOpener** - Puzzle to ponder with a surprising outcome.

For members: PiDayClassOpener-solution.pdf

Early in the week before π day, present the challenge of seeing who can memorize the first 100 digits of the number pi. This is an opportunity for students who have a talent for memorization to shine. Bring a pie to class as a reward for anyone who can pull it off. **3.1415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679 ...**

**Activity#2-What is Pi?.pdf - **The logic of finding the perimeters of inscribed and circumscribed polygons as the number of sides to the polygons increase.

For members: Activity#2-What is Pi-solution.pdf

**Activity.#3-ApproximatingPi.pdf** - Students calculate the perimeters of a 4-sided regular polygon (square) and a six-sided polygon (hexagon); divide those perimeters by the shapes diagonal and approximate π. For members: Activity.#3-ApproximatingPi-solution.pdf

**Activity#4-measuring-pi.pdf **- Students spend a day of class measuring various round items; practicing exact measurements; long dividing their measurements by the radius measurements; and comparing their resulting ratios. For members: Activity#4-measuring-pi-solution.pdf**
Activity#5-HatSize.pdf** -

**Hat size is a measure of the diameter of your head ... but how do you measure that ... through your ears?**

**Activity#6-VariousWaysToApproximatePi.pdf **- Let students try their hands at different ways of calculating pi with formulas that have been used to approximate its value. For members we have: Approximations-Pi-solutions.pdf

GeoGebra has a great demo to show that the area of a circle can be shown as any number of pie slices rearranged into a parallelogram. The GeoGebraTube Area of Circles applet was created by Anthony Or, Education Bureau, Hong Kong. Brian made a video to show you how to use the GeoGebra applet or to simply show your math class.

You might also consider some of these timeless yummymath tasks that let students apply pi such as:

Largest Cup of Coffee Ever! | Is this possible? | Monster Cake | Gumballs galore |

Pizza deals | Penny Wars - which has the most? | Huge Key Lime pie |