Mathematicians as far back as the Ancients knew there must be a special relationship between the elements of the circle – a figure that may vary in size, but always retains its same shape. The fascinating part of the formula? A mathematical constant now known as Pi.

**Pi** is the ratio of the circumference of a circle to its diameter. While no one knows for sure who discovered Pi, we know that:

- The earliest written approximations of Pi came from Egypt and Babylon
- Archimedes discovered the first three digits of Pi (3.14) through a geometrical approach that used polygons
- The Pi symbol was introduced by an English mathematician named William Jones

To students, Pi may often seem like something that was made up to make math more difficult, but it has a tremendous number of uses in the real-world. Raytheon’s MathMovesU has a great infographic that shows some of the different ways Pi is used in the real world:

Now that we’ve explored pi’s history and how it is used in the real world, let’s see how we can use pi to track our own travels.

Ever wondered how far you’ve walked if you walked in a circle? Ever circled the perimeter of a beautiful garden or architectural feat designed in the shape of a circle?

A simple application of pi can show you the distance you’ve walked. If you know the diameter, or the greatest length across the circle, we can simply multiply this by pi to arrive at our circumference. Check out the example graphic below from MathIsFun.com:

A classroom activity that greater demonstrates and explains the functionality of pi is to recruit physical and virtual robots to calculate the distance a vehicle has or will travel. Check out the activity below!

We have a few other ways for you to incorporate robotics Pi Day activities into your classroom. You can:

- Investigate the Pi-related lessons built into our curriculum
- Download our free Pi Day activity booklet
- Use our LEGO or VEX STEM CAD Workbook, which includes an entire chapter on the relationships between wheel radius, diameter, circumference, revolutions, and distance. In addition to providing Pi-related activities, the STEM CAD Workbook Bundle also allows you to:
- Introduce students to the language, concepts, and tools of engineering, such as technical sketching, interpreting technical drawings, measurement, converting units, simple machines, the engineering process, time management, and teamwork
- Use differentiated instruction to teach students at their current level
- Introduce concepts using a scaffolded approach to learning

**The STEM CAD Workbook Bundle includes:**

- FREE SnapCAD Instructional Videos
- FREE Curriculum Edition SnapCAD Software
- FREE Teacher’s Guide: includes Workbook preview
- Robotics Workbook
- Additional SnapCAD models

**To Learn more, click the links below:**

STEM CAD Workbook Bundle: Building Simple Machines and More with VEX IQ and Snap CAD

STEM CAD Workbook Bundle: Building Simple Machines and More with EV3 and MLCAD