Understanding Pi

Students learn the mathematical value of pi through the process of measuring circumference. Students conduct hands-on calculations for cylindrical objects, demonstrate the properties of a circle, and discover for themselves how pi works.

**Grade Level:** 7-9

**Subject Matter:** Mathematics

**Curricular Uses:** Pi, Basic Geometry, Irrational and Rational Numbers, Ratios

**Learning Objectives**

**Students will be able to:**
Measure the circumference of an object to the nearest sixteenth of an inch.

Measure the diameter of an object to the nearest sixteenth of an inch.

Explain why 3.14 is used as an approximation for pi.

Demonstrate why one may compute pi by dividing the circumference of an object by its diameter.

Discover and apply the formula for calculating the circumference of an object by using pi.

Learn the definitions of rational and irrational numbers and see specific examples of each.

Understand why pi is an irrational number.

**Use of Internet:** The Internet is used as a research tool. It also helps students see and hear visual and musical representations of pi.

This lesson was developed by Emily Crawford, Linda George, and Tracy Goodson-Espy.