Around the world, March 14th has become regarded as Pi Day, a day when we recognize the never-ending irrational number that represents the circumference of a circle divided by its diameter. Pi is an important number and a confounding one, too. Whatever the size of the circle, pi is always the same, with the first six digits of 3.14159. If you want to be really specific, you can kick-off your Pi Day activities at exactly 1:59 p.m. Pi has been calculated to over ten trillion decimal points without a repeating sequence.
Regardless of the age of your students, teaching them about pi is a good thing. Basic mathematics is demonstrated when you discuss this granddaddy of all irrational numbers. A geometry lesson shows how to use pi to find out find the diameter or circumference of a cylinder then calculate its area with an additional height measurement. And you can incorporate a bit of history, too. Pi is an ancient concept, first discovered by the Babylonians nearly 4000 years ago and further refined by Archimedes more than 200 BC.
Explaining pi to younger students
Regardless of a student’s age, they can be taught about pi. The website Quora suggests using a simple nail and string in their article “How do I explain pi to a five year old?”. You pound a nail into the ground and tie a string to it. At the other end of the string, tie on another nail and then trace a circle. Then tell the students that the length of the circle is pi.
Activities for grade school students
Using string and a clean, empty soup can, wrap the string around the circumference of the can. Cut the string where it meets the beginning end. Then stretch the string across the diameter of the can, and cut this measure. Repeat twice and you should always end up with three equal lengths of string with a little left over (pi!). Check out Exploratorium.edu for additional activities.
Create a pi chain with loops of construction paper in different colors representing each number. Students will be able to see that there’s not a pattern to the extending decimal points.
Activities for middle school students
Bring in a variety of round shaped objects, such as a hula hoop, car or bike tire, dinner plate, Frisbee or cylinders such as an oatmeal box or coffee can, and have the students measure the diameter and calculate circumference using pi.
- Check out TeachPi.org with more than 50 activities suitable for younger students.
- Wolfram MathWorld offers a variety of formulas and other resources for high school students.
- Show students the historic timeline of pi here.
- Visit the official site for pi at PiDay.org for additional teacher activities.
- Check out what the first million digits of pi looks like.