Explain how the number 3.14 for pi was determined. Demonstrate that by dividing the circumference of an object by its diameter you end up with pi. Discover the formula for finding circumference using pi, and demonstrate it. Divide class into groups of two. Give materials to student teams.
Students can then find the average number for the class.
Explain to the students that they have just discovered pi, which is very important in finding the circumference of an object. Have students come up with a formula to find the circumference of an object knowing only the diameter of that object, and the number that represents pi. Students must prove their formula works by demonstration and measuring to check their results. Students may also share what they have learned with other members of the class. Give students three problems listing only the diameter of each object and have them find the circumference.