# Tween Us

## What is Pi Day? Facts about Pi, Pi Day and Pie

Today is March 14, which can be written numerically as 3/14. It also Pi Day. Pi is the Greek letter “π” and it is also the symbol used in mathematics to represent a constant — the ratio of the circumference of a circle to its diameter — which is approximately 3.14159.  It is usually shortened to 3.14, hence the celebration on this calendar date.

Facts about Pi, or π, from PiDay.org:

• an irrational and transcendental number, Pi will continue infinitely without repetition or pattern;
• Pi has been calculated to over one trillion digits beyond its decimal point;
• Pi is a recurring constant that has been studied throughout history and is central in mathematics as well as science and engineering;
• Pi is often introduced in middle school or junior high math classes.

Facts about Pi Day:

• On March 12, 2009, the United States Congress passed a resolution recognizing Pi Day. You can find the text of the House Resolution here;
• Memorization contests are popular - see which family member can memorize the most digits of Pi
• Pi Day has inspired not only mathematicians, but also musicians. You can watch “The day they discovered Pi…” by Ken Ferrier and Antoni Chan via YouTube, or find Pi Day music, including raps and carols, here, or check out Pi Diddy's hit single “Loving Pi” ;
• Find more ideas for how to celebrate Pi Day here and here;
• March 14 is also Albert Einstein's birthday. He was born in 1879. My favorite Einstein quote: "Imagination is more important than knowledge. For knowledge is limited, whereas imagination embraces the entire world, stimulating progress, giving birth to evolution."

Pie and photo by Amanda Hoffman

• here are some tasty pie recipes for Pi Day from NPR’s Doreen McCallister, or use these recipes from the South Side PieChallenge cookbook;
• You can calculate the circumference of a pie with this formula 2πr (r = radius), and area of a pie with the formula π r squared;
• The most popular flavors of purchased pie: Apple, pumpkin, cherry, blueberry, and Dutch apple;
• Pie is both fun to eat, and fun to read about, especially in Sarah Week's book Pie.
• The first pies were filled with meat and called "coffins" which means "basket" or "box." Find facts on the history of pie here.

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Filed under: Education, Food &amp; Nutrition, Holiday

Tags: Pi, pie

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• ### Meet The Blogger

#### Shannan Younger

Mom of a tween, working hard to understand how best to parent this tricky and fabulous age group. You can email at TweenUsBlog [at] gmail [dot] com.

• ## Chicago Parent

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