There are some topics or problems that have captured the interest of mathematicians for ages. Calculating pi is one of them. While students often encounter pi in the mathematics classroom when applying various formulas, rarely do they use or explore pi in other contexts. This marvelous infinite number we know as pi shows up in many fascinating and mysterious ways. It can be found everywhere, from astronomy and probability, to the physics of sound and light. It is one of the most important numbers that exists.

Help your students discover the number that has intrigued mathematicians for centuries. Learn different ways pi has been calculated through the ages, use pi to figure out your hat size, perform a variety of experiments to estimate the value of pi, or relate pi to the alphabet. These interesting and exciting activities encourage higher order thinking and offer a complete overview of this important number while giving students practice in important math skills.

This guide includes detailed lesson plans aligned to NCTM standards and reproducible student worksheets. Use them for Pi Day (March 14), as an enrichment or extension to your existing curriculum, or to challenge your ablest math students.