Circumference and the Dragon of Pi

Lesson 2

Instructional Objectives:

Students will:

Investigate, describe, and reason about the results of subdividing, combining and transforming shapes using models and representation.

Explore the effect on size when objects change under simple transformations.

Time Needed: two 40 minute periods

Materials: Sir Cumference and the First Round Table (available from Scholastic, Barnes and Noble, and a variety of other book sellers), paper, markers, prepared worksheet, four circular objects( such as plates cups, lids, etc.), a calculator, string.

Advanced Preparation:

Purchase the book

http://amazon.com/exec/obidos/ASIN/1570911525/002-9350959-4185659

Download and print the Sir Cumference and the First Round Table worksheet from the PBS website.

PDF File

http://pbs.org/teachersource/mathline/concepts/literacy/Act1Student.pdf

PDF Answers

http://pbs.org/teachersource/mathline/concepts/literacy/Act1Solution.pdf

Illustrative Materials:

Show students this animation that illustrates circumference.

http://harcourtschool.com/glossary/math/definitions/circumference.html

Procedures:

Activity One

Have students brainstorm what they believe they know about radius, diameter, and circumference. Before reading the story ask students to focus on the math vocabulary that will be in the story.

Read the story aloud with the class having them focus on radius, diameter, and circumference.

Give students the worksheet that goes with the story.

http://pbs.org/teachersource/mathline/concepts/literacy/activity1.shtm

PDF File

http://pbs.org/teachersource/mathline/concepts/literacy/Act1Student.pdf

PDF Answers

http://pbs.org/teachersource/mathline/concepts/literacy/Act1Solution.pdf

 

Activity Two

Let students investigate some ideas about circles. They will need some string or yarn, a calculator, a recording sheet, and a ruler or meter stick.

Give students four circular objects. Have them measure the distance around (the circumference) and the diameter, and record the measurements on the table in the worksheet. After they have made the measurements, let them use a calculator to divide the circumference by the diameter (C ÷ d). Have students record their answers on the worksheet.

Assessment:

Score the results of the worksheet. There are ten problems so you can use a 10 point scale.

Extensions:

Math Goodies lesson on Circumference of a Circle

http://mathgoodies.com/lessons/vol2/circumference.html

or aaamath.com

http://aaamath.com/geo612-circumference-circle.html

Homework: Bring in 6 circular objects to measure for the next day's lesson.

Lesson 1
Lesson 2
Lesson 3
Lesson 4