If you are involved with schools or mathematics at all, you know that today is Pi day. Pi is a number that never ends and for some odd reason, many kids like to memorize as many numbers as they can. Pi Day is celebrated on 3/14 representing the first three numbers of this irrational number. My boys, who always did well and liked mathematics, could never really be bothered with the memorization. However, I do remember my youngest tying with another student during his elementary days for being able to recite most numbers. I think he was in 3rd or 4th grade. After that, he just did not want to bother – I think he came to realize there was not much point in just memorizing the numbers. He has a great memory (some of his teachers have thought it to be photographic), so the memorization wasn’t even much work for him.

Pi is the ratio of a circle’s circumference (distance around the circle) to its diameter (distance across the circle) or 3.14159……on and on without repeating……counted last in 2013 to over 12 trillion places (see NOVA video below).

Over the years, and especially during the summer, when I used to do a lot of enrichment with my boys in an attempt to keep them academically “up to speed,” I started looking into what pi was really about – what it signified. Yes, I took geometry and trig in high school, doing quite well on the New York State Regents exams. But, that was then, this is now. The fun has increased around this unique and essential number over the years, and so have the ways to help students really gain an understanding of pi. Here are some informative and interesting videos I found on the number pi.

This video, I just found, explains not only Pi but also the Fibonacci Sequence which is pattern of numbers that occurs frequently in nature. I am especially fond of Fibonacci numbers and how the sequence can be represented in the natural world.

Pi & The Fibonacci Sequence by NOVA.

But, with the popularity of memorizing as many numbers as you can and reciting them in a minute as part of a school wide contest, the meaning of pi has gotten lost, in my opinion. Elementary students know the word “pi” and that it stands for a non-repeating number. Middle school students might be able to give you a definition of what pi signifies. But, beyond that, everything that can be calculated using pie can get very complex and interesting, especially if students can visualize how this number is derived.

Below, I have listed another recent post about why we really don’t need to be memorizing all those digits…Astrophysicists do not not even use all that many pi numbers after 3.14159…. they only take the number out to 12 places, according to this post from the NASA’s Jet Propulsion Laboratory!

Do your students know visually how pi is derived? Probably not. I looked for a visualization of this some years ago and thought it was the coolest thing when I found it. I am hoping I can find it by the end of this post!

Pi is an irrational number that is an essential piece of many mathematical calculations. This post from LiveScience explains. This piece states that some computer simulations have calculated pi out to 22 trillion digits! Wow-za!

I just found this video (while still searching for the other one) that is decent and tells what pi is used for in real life, modern day applications. I like it. There are a lot of facts and not any weird music or narration, but it is still missing the unraveling of the circumference to show the ratio. My 19 year old even remembers the video I found and we both agree he was in middle school when I found it.

I like this explanation from Popular Mechanics Magazine online that has three animations to help one understand where the number comes from, other than a pat answer of the ratio of circumference to. diameter, expressed as a decimal or fraction.

It is the closest I have come to the unrolling of the circumference to show how pi is derived. Unfortunately, it is not the video I’ve been searching for. I have gone back in my emails as far as 2014, and still not found the link. If my son is correct, and it was when he was in 8th grade, 2013 would be the year. It might have even been Pi Day, 2013!

On another, somewhat related note, I love pie.

If I were to celebrate pi day, I would do it with pie! This post is dedicated to all those pi/pie loving teachers I know that are out there! I hope you enjoyed your day!