Circumference and the Dragon of Pi

Lesson 4

Instructional Objectives:

Students deepen their understanding of the measurement of plane and solid shapes and use this understanding to solve problems:

Understand the concept of a constant such as pi; know the formulas for the circumference and area of a circle.

Know common estimates of pi (3.14; 22/7) and use these values to estimate and calculate the circumference and the area of circles; compare with actual measurements.

Time Required:

This activity can be done in as little as 40 minutes or you could spend the entire day doing Pi Day activities. There are so many activities that can be done with this unit that some teachers have declared Pi Week.

Advanced Preparation:

Write a letter to parents asking for donations of pies a few days in advance.

Vocabulary: circumference, diameter, radius, geometry, pi

Materials: pies, strips of paper, paper plates, plastic forks

Activities:

Pi Day can be held any day, but works best on March 14^th (3/14). There are many ideas on how you can incorporate Pi Day into your classroom. My class brought in a variety of pies that were different sizes. The diameter of each pie was measured. Then strips of paper were cut that were the same measurement as the diameter. The students were to see how many strips of paper were needed to fit around the pie. The class was able to see that three of the paper strips, plus a small portion of another strip were needed to fit around the pie. They could see that they needed 3.14 strips of paper. This worked for every pie, no matter what the diameter of the pie was. This is a great way to let students visualize the concept of pi. The students also enjoyed eating the pies at the end of the lesson! Information on Pi Day can be found at the following sites:

http://ael.org/eisen/treasure/tc0300.htm

http://mam2000.mathforum.org/t2t/faq/faq.pi.html

http://mathwithmrherte.com/pi_day.htm

Illustrative Materials:

Pi Day (3/14) is also Einstein's birthday. Here is a fun card that students can send in honor of the occasion.

http://freewebcards.com/cards/uselessholidays/pi_day.shtml

Samples of Pi Day activities from a middle school to show your class can be found at:

http://ga.k12.pa.us/academics/MS/PiDay/Index.htm

Homework:

Digest all of the pie that got eaten.

Lesson 1
Lesson 2
Lesson 3
Lesson 4