Pi isn’t just delicious. It seems like everything has a day now, but Pi day might be the most scrumptious one yet.

## What is Pi?

Pi is a mathematical constant. It is a ratio that describes the relationship between the length of the outside of a circle (circumference) and the length across (the diameter). That relationship is that the circumference of a circle is a little more than 3 times the diameter of a circle. In fact, it is 3.14159… times the diameter. Those … means that this number goes on for infinity. To make things easier, we typically think of it as 3.14. It is often represented by the Greek letter pi, π.

## What is Pi day?

The number 3.14 looks really close to March 14th in countries that use dates with the month and then the year (like the U.S.). That means that 3/14 is Pi Day and there is no better way to get your STEM fun on than with some pie. It is really just an awareness day and another opportunity to make STEM fun.

## Ideas for Pi Day Activities

Pi is used in many fields. Examples of disciplines that use it include astronomy, architecture, engineering, navigation, and construction.

### Astronomy ideas

My go-to for astronomy ideas is always NASA and as usual, they don’t disappoint. ** NASA pi day activities **include tons of great problem sets using pi and REAL WORLD data. Pi day is a perfect day to set up your own mock space station or mission control.

You could also take the day to visit one of the many great NASA locations to see the working of the space program. We’ve been to the Huntsville Space and Rocket Center, the Kennedy Space Center in Cape Canaveral, and the Space Center in Houston. All three have great exhibits and activities.

### Architecture Pi Ideas

Anytime that we can connect an abstract concept (especially a math one) to real life problems, it helps to get kids interested in the topic. This is a quick read with some ideas about how** architects use pi in their careers** (with an ode to pie included). More pi ideas related to architecture:

Why do we find circles beautiful?

### Engineering Pi Ideas

Pi isn’t just for measuring the area of a circle. Pi lies at the heart of any technology that involves rotation or waves which includes much of mechanical and electrical engineering which includes a broad range of things from the rotating parts of engines and MRI machines to waves that allow for telecommunications to occur. Some engineering pi ideas:

Bridge building (strength of the arch)

**Navigation Pi Ideas**

Navigation of the earth is based on arcs so pi is important for navigating the globe. When planes fly great distances, the plane is not flying in a straight line, but an arc. The same is true for any more of transportation really. The calculations are important to get to your destination, but also other things like gauging fuel, and other supplies. For most ways to calculate a location on the globe, pi is important.

### Delicious Pi Ideas

Cookies, Cakes, PIES, and Pizza are all great additions to any Pi Day Activities. Just makes sure to have the kids do some calculations before they eat everything in sight.