My Favorite Pieces of Pi

Sprial 1

Over the past couple of years I’ve dedicated a number of posts to the way I’ve been looking at Pi.  In recognition of the upcoming Pi Day, I’m reposting some of my favorite images from these past posts.

Though not very beautiful the following image, which I did in as an Excel document, is one of my favorites, as it visually illustrates different common estimations of Pi, and how they compare to each other.

Pi- comparisons of approximations
Pi- comparisons of approximations
Zooming in on PI

From these images, it looks to me that there’s a  difference, though not much,  between 3.14 and 3.141592 though the difference between 3.1416 and beyond is indistinguishable to mere mortals.

I wrote a post about a cut-and-paste pi project. It’s illustrated with 19 photos. The link to this post embedded in the caption below the photo.


What I like most about this project is that it lets you hold a piece of .14 in your hand.

I also made some coloring pages, for pi, which I collected in a Pi Coloring Book-style pages pdf.

pi big fraction

This fractional representation of Pi is the most accurate estimation of pi with a denominator under 10,000. Here’s the way I colored it in:

The most accurate fractoin representing pi with a denominator less than 30,000
The most accurate fractoin representing pi with a denominator less than 30,000

Here are a couple more of my Pi coloring pages:

PI symbol


pi 22 7
a useful estimation of pi


Then, I decided to try my hand at creating a one-page explanation of  Pi :

Circumference wrapped by by 3.14 Diameters, or 2(pi)r
Circumference wrapped by by 3.14 Diameters, or 2(pi)r

This past summer my cousin was visiting. He needed to figure out the size of the rim on a wheel of his bicycle, and was having trouble with the measurement because it was circular. You know where this story is going, right? I suggested that he measure the diameter then multiply by 3.14. He seemed politely interested, but I’m not sure if think he actually considered trying it. After all, it sounds like hocus-pocus.

Happy Pi Day!


5 thoughts on “My Favorite Pieces of Pi

  1. Paula, the last graphic was amazing. It really explained pi is a visual sense. I’m sure it will help anyone who is non-mathematical make sense of pi. Great job! And thanks for sharing.


  2. My favorite Pi Day activity is similar to your graphic. Students trace a circle on cardstock and draw a diameter of the circle. Cut pieces of yarn as long as the diameter (hold the yarn across the circle along the diameter and cut). Glue the yarn to the circumference of the circle. 3 will almost make it around but there is a small gap…that’s the .14. You can almost hear the lightbulbs clicking on!

    Liked by 1 person

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