# March 2020: Celebrating Pi Day

What is it about pi that makes it so intriguing? Is it the fact it never ends? Is it the fact we all remember the formula we learned in math class and still use when we are sewing, or creating a playground, or simply drawing a circle? Pi is the ratio of the circumference to the diameter of a circle, which means that the circumference of a circle is equal to 2 time pi times the radius of the circle. The common formula we use for that is C = 2 pi r (Tip: To type the pi symbol on a Mac, hold down the option key and type the letter P. On Windows computers and on a Chromebook, hold down Ctrl+Shift+U and type 03C0 and hit the space bar for a lowercase pi)

Whatever the reason for our infatuation with pi, the world has celebrated Pi Day on March 14th each year since 1988 because the first three digits of pi are 3.14 and reflect the date. Some pi-lovers celebrate Pi Day at exactly 1:59 to celebrate the first six digits of pi which are 3.14159! (There was a really big celebration in 2015 when, on March 14, 2015 at 9:26:53 am, the first 10 digits of pi, 3.141592653, were honored!) The History Channel includes an interesting overview of the birth of Pi Day here.

This celebratory day is meant to increase interest in math and make it fun! Museums, schools, and even virtual worlds have parties and activities that involve round items like apple pies, quarters, pizza pies, and the moon. (And March 14th is also Albert Einstein’s birthday, so you can build some activities about him into the day, too!)

#### DISCOVERY EDUCATION RESOURCES

Discovery Education celebrates Pi Day each year with gusto. They have tons of resources to help teachers incorporate this fun holiday! Some include:

- Lesson Starters: Hooray for Pi Day is a lesson for grades K-5 that has students watching some relevant video segments, and then, using popsicle stick puppets of themselves, creating a short shoebox video explaining pi using relevant screenshots from the video as the background. Older students might create the video while standing in from of a green screen and giving a “newscast” about the importance of pi in math and science.
- Elementary students will enjoy the short video, Attributes of Circles, which includes information about the relationship between circumference and pi.
- There is a wonderful video for middle and high school students, Pi Day: Live from NIST, which “presents a detailed tour of the National Institute of Standards and Technology (NIST) and explains how different standards of measurement are calculated. The program also examines how pi factors into the many different facets of standardized measurement”.

Although Pi Day is a special day, the inclusion of pedagogically-sound activators and summarizers should also be part of the celebration so students get time for both creative thinking and reflection. The Discovery SOS series includes a wonderful group of instructional strategies to help develop mathematical thinking. Some of these include ways:

- To help students justify and provide reasoning for mathematical solutions, the “Pick a Card, Any Card” strategy (CDN) “involves students as active participants in group discussion. The teacher uses prepared question cards and encourages students to discuss content, using evidence from the media to back up their claims and opinions”.
- To help students draw conclusions and make connections, the “Silence is Golden” strategy (CDN) is “meant to focus students’ attention on imagery, making inferences, and predicting future content. Students describe what they see and teachers can ask guiding questions about the imagery to allow for deeper thinking”.
- To help students represent and communicate mathematical solutions, the “Make it Concrete” strategy (CDN) “uses concrete, or shape, poems to allow students to demonstrate understanding. Students reflect on their learning and create a visual to represent something they have learned from a media resource”.

#### OTHER RESOURCES

- The Time and Date site, a place where all manner of global celebrations are covered, includes interesting information about Pi Day. I learned about a new pi celebration!

Because everyone should be able to enjoy a fun mathematical holiday, people in countries that follow the day/month (dd/m) date format, honor pi on Pi Approximation Day. The date of Pi Approximation Day – July 22 – when written in the day/month format or 22/7 corresponds to the fraction (22/7) that pi is usually depicted as.

There are other days during the year when one can honor pi. Some of these are:

- March 4: The day marks the passing of 14% of the 3rd month of the year.
- April 5: By this day, 3.14 months of the year have passed.
- November 10: The 314th day of the year (November 9 in leap years).

- The Teach Pi site has collected over 50 activities to use to help celebrate Pi Day. Some of these include:
- Have students learn the first 100 digits of pi by memorizing this great video by ASAP Science, the guys that brought you my favorite instructional video of all time, the original Periodic Table Song from 2013 and the updated version from 2018. Turn on the subtitles/close captions on the YouTube video to make it easier for students to follow along.
- The PiDay site showcases the first million digits of pi!
- The We Are Teachers site offers “31 Mathtastic Pi Day Activities for the Classroom“, including having students create “pi-ku” poems in the format of haiku (5 -7-5) but dealing with the topic of pi!
- Wolfram Mathworld provides ideas on using mnemonics to memorize pi out to seven, fifteen, and 31 digits!
- PBS Learning Media has collated over fifty ideas for celebrating Pi Day for students in grades K-13+.
- MathGeekMama offers some original Pi Day lessons and support materials as well as linking to tons of other Pi Day activities on the Web!
- Many teachers share their Pi Day bulletin board designs on the Web. Take a look!

#### FEEDBACK

How do you celebrate Pi Day in your classroom? What are some ways you have celebrated it in a content area other than math or science? Please share your thoughts, ideas, and links to classroom set-ups, images, or videos your students or you have created!