In the past, I’ve not really been a fan of Pi Day (please don’t revoke my math teacher card!). Most of the time it just seems like a party day that ends up being a waste of time that I could’ve *really *used as an extra instructional day (Oregon always gets a ton of snow at the end of February, which makes early March *stressful*). That said, I love to celebrate and have fun, so I’ve been thinking and thinking about how to have the best of both worlds! I think I’ve finally figured it out.

I plan on doing two things with my students. The first is a circle investigation that lets them discover what pi is, and then they derive the formulas for the circumference and area of a circle. My favorite part is the proof of the area formula for a circle…I think I have it laid out in a really cool way that is also very pattern-based for students. It also allows them to built upon their prior knowledge, which is fantastic!

For the record, all of my students already know the formulas for circumference and area, but I strongly doubt any of them actually know *why *those formulas work. Most of my students have been regurgitating those formulas for *years *without actually knowing one bit of the “why” behind why they work. So, from Algebra 1 to Pre-Calc, I think all of my students will really benefit from the conceptual understanding and process of deriving formulas that are introduced in this activity.

In the first investigation, students are to find and measure 5 circles using string and a yard/meter stick. I’m going to let my students go on a bit of a circle scavenger hunt around to school that way they’re not all using the same ones, but I also have 5 circles to print out for classes/students that I know might not be able to handle that amount of freedom. I plan to have my students work in groups of two or three.

After students are done with the three parts of the investigation, they get to move onto the coloring activity to apply what they’ve learned. I don’t know what it is about coloring, but all of my students LOVE to do these types of activities. Regardless of age or gender, they are all down to color. This activity is also self-checking because of the way it’s set up. There are 10 problems in total that are broken up into two columns. Each of the answers from the first column will match up with another answer from the second column. The way that the problems match up creates the color-coding key for the picture.

I would love to know what you do in your class to celebrate Pi Day. Please leave a comment below, I’d love to hear from you!

-Audrey

If you would like to use these activities in your own class, you can find them **here**!