How many celebrations are there in your math class? Each year on March 14th many classrooms break from their usual routines to observe the festivities of "Pi [] Day" because the digits in this date correspond with the first three digits of (3.14).

Teachers use this date to engage students in activities related to the history and concept of . Students are often familiar with before this day and the projects and activities associated with Pi Day are meant to enrich and deepen the students' understanding of the concept. Activities may include investigations of the value of by approximating the ratio of the circumference to the diameter of a circle. Students may also share their own Pi Projects with their classmates. Some teachers choose to end their Pi Day celebration by eating pie!

If you are looking for some ways to celebrate math in your math class, or if you would like to suggest some school-wide thematic activities, you are certain to find ideas on this page to help you design a Pi Day that students will enjoy. If honoring is not enough of a reason to make this day special, keep in mind that March 14 is also Albert Einstein's birthday.

Students' mathematical understanding can be enhanced through literature selected for its mathematical connections. The following books are available through Amazon.com:

π Day 2014 - Scott Steketee

In his Sines of the Times blog post, Steketee shares a few of his favorite circle dissections, including Jaws of Pi, Coiled Pi, Mountains of Pi, and Pi Explosion.

123 Greetings

Send a Pi Day greeting card ...more>>

Activities & Information Supporting Pi Day Celebration - Carolyn M. Morehouse

A lesson plan for Pi Day activities, Pi Songs, and a Pi Trivia Quiz are among the resources Carolyn has provided.

American Pi (song)

Lyrics are by Lawrence Mark Lesser and he suggests singing it to the tune of Don McLean's "American Pie."

Area of a Circle - Henri Picciotto

If we accept that the circumference of a circle is 2πr, we can deduce the area formula with the help of this applet.

Derivation of Pi - Jon Basden

Students use real-world objects to understand the concept of a constant such as pi.

Determination of Pi - Alexander Bogomolny

This lesson presents an interesting alternative to the customary game plan for the determination of pi. Bogomolny's lesson presents pi in the framework of similarity, which makes the existence of pi self-evident. Approximation of pi does not require several objects. Pi can be approximated by taking measurements of a single circular object with different tools and different techniques.

The Digit Connection - Lizzie

A tribute to the number Pi through music, poetry, and fiction. (Meet Sailor Pi!) Also includes a brief history of Pi with some ways to calculate it, a quote collection, and ways to celebrate the number - even if it's not Pi ...more>>

Fun Pi Facts & Pi Day Activities - The Exploratorium, San Francisco, CA

Pi Day celebrations, Pi music, links, beads, and pie. A certified 98% content-free page. ...more>>

Math Library: Arithmetic/Early: Number Sense/About Numbers: Pi

Pi resources that have been collected, organized, cataloged and annotated from diverse sources.

Pi Day: Making a Pi Necklace - Diana Funke

Diana Funke teaches mathematics at Davisville Middle School in North Kingstown, RI. Her students make a Pi necklace for Pi Day to reinforce the idea that some numbers never repeat or end. They assign a color to each digit (including 0) and then...more>>

The Pi Search Page - Dave Andersen

Search the first 50 million digits of pi for any numeric string up to 120 digits. The page also documents a few observations about pi's numeric strings, including self-locating strings, palindromes, and month-day combinations....more>>

Π for Regular Polygons? - Henri Picciotto

Is there a π for regular polygons? Use these slides for a discussion in cases that do not require trigonometry. Follow up by using basic trig in the last activity (Lab 11.8) of this PDF of Geometry Labs.

Pi Through the Ages - MacTutor Math History Archives

A history of Pi: the Rhind papyrus (Egypt), Ptolemy, Tsu Ch'ung Chi, al'Khwarizmi, Al'Kashi, Viet, Romanus, Van Ceulen, Gregory, Shanks, Lambert, Euler, Buffon, and many more, with other Web sites and 30 references (books/articles). ...more>>

The Story of Pi

Video segments available for viewing on the Web or the videotape and workbook is available at cost from Project MATHEMATICS!

Taxicabs and taxi-π - Henri Picciotto

Learn about taxicab geometry in this PDF of Geometry Labs 9.1 and 9.6.

1441: Circles Around [print version]

Use this exploration problem to discover the relationship between
circumference and diameter.

1165: Sprinkler Spray [print version]

Compare the radii of three sprinklers in Lily's garden.

1094: Accuracy Please [print version]

Considering precision, accuracy, and appropriateness in finding the
volume of a cone.

650: Peanut's Back Yard [print version]

Peanut, the overexcited dog, makes 40 laps around a stake and travels a total distance of 1 mile. If his bowl of water is 20 feet away from the stake, can he get a drink?

1142: Pi Day, Let's Eat Cake! [print version]

In honor of Pi Day we will be comparing the volumes of slices taken
from round and rectangular cakes.

614: Pizza Pie [print version]

Use the given information to decide how many slices of the small pizza
would be equal to or greater than 3 slices from the large pizza.

3536: How Fast Is a Minute? [print version]

How many feet does the tip of the minute hand travel in an hour on the clock on Philadelphia's City Hall Tower?

3632 Practicing for the Winter Olympics [print version]

What is the length of the semicircular path Sonya skates across the ice rink?

3404 Bella's Bagel Bakery [print version]

How much more area is covered with cream cheese on the large bagel than on the small bagel?

4520 Baking Blackberries [print version]

Which baking dish is best to use?

1456: Dot.Com Derby [print version]

Three "dots" run a race around a circular track in an unusual manner. You must determine the winners in two categories.

880: Round the World on a Wire [print version]

A wire is wrapped around the equator of the earth. Then extra wire is spliced in. Can you walk under the slack that results?

1107: Equilateral Triangles and Circles [print version]

Two vertices of an equilateral triangle are on the diameter of a circle whose area is 49 pi. The other vertex is on the circumference of the circle. What's the largest possible area of the triangle?