Each year on March 14, math lovers come together in the universal celebration of National Pi Day. But you don’t have to be a mathematical scholar to enjoy (or understand) what Pi is all about. Let’s explore!

**What is Pi?**

Pi is the circumference of a circle (the distance around the circle) divided by its diameter (the distance across). So take at any circle anywhere around the world at any size. The entire distance around the circle will be approximately 3.14 times its length across. Because 3.14 are the first digits of pie, 3/14 (March 14^{th}) is designated as National Pi Day each year.

Pi is an irrational number, which means it has an infinite (limitless) number of digits. No matter how many decimal places are calculated, pi will always be an approximation. Its decimal representation never ends and never repeats.

Graphing is an early math skill that most likely begins in Kindergarten, so the easiest way for children to understand that pi keeps going, and going, and going, is set up a graph. In this art + math project of a skyline, the buildings each represent a number in pi.

## For this project, you will need:

- Graphing paper
- Marker
- A printout of π
- A watercolor set

First, count out how far you will take your skyline, which will determine how far you go with your pi print out. Begin by lightly writing out pi on the bottom of the graph, and then run 1-9 up the side of the graph. (Of course your budding mathematician can just count the squares up, but this does definitely takes a while). We determined that the decimal point would be the same value as 0.

Next begin to graph each building. We found it was easiest to count the squares up, mark it with the maker, *then* connect it with the building before it. This will take time, but it really does resemble a city skyline pretty quickly.

Next, color in your buildings. This was a welcome activity after the tedious nature of the graphing!

Looks great! And looks very much like a city’s skyline! Now it’s time to use the watercolors.

Erase your numbers so you have a clean slate.

Create any kind of sky you’d like – sunset or sunny day.

Turned out great! A physical representation of the mathematical truth of pi.

Used some glitter and glue to make some “pi’s in the sky”. Happy Pi Day!

Save it for later!