Fun with Digits

Hold a classroom or school-wide contest for the recitation of the most digits from memory. Offer a free pizza pi(e) to the winner.

» You should expect the winner to memorize about 30 or 40 digits, but every once in a while, a student like Gaurav Raja (Roanoke, VA) comes along. He’s up to a whopping 10,980, finally securing the North American record.
» Keep records from year to year, as a Pi Day Hall of Fame, and notify your class of the all-time school best.

On as many index cards as you have students in class, write two digits of pi on each card, in large, clear print. (First card: “3 .” Second card: “1 4”, etc.) Shuffle the cards and hand them out to the class. Display on the overhead projector the first ~70 digits, and tell the students to find their own pair of digits in pi, then stand up and silently assemble themselves in order. At the end, have them recite the digits as quickly as possible, two by two, around the room. See if the class can get a quick rhythm going!

» At the end, have them recite the digits as quickly as possible, two by two, around the room. See if the class can get a quick rhythm going!
» All this might help them appreciate the true randomness of the digits, though they might discover a few repeated pairs along the way (making for an interesting silent negotiation!). Hint: the numbers 32, 38, and 79 will appear twice, and oddly enough, in two clusters of six digits!

As a class or grade, create a pi chain with loops of construction paper, using a different color for each of the ten digits.

» Students at Dallas H.S. in Dallas Township, PA created a pi chain that was 7,147 digits long. It stretched nearly half a mile.

Take an overhead photo of your students outside, forming the first several digits of the number. Third graders can form the 3, first graders the 1, and so on. A great image for the local newspaper!

» This precise photo was taken at the International School, Borneo (ISB) in March, 2005.
» Why not make the math teachers the decimal point?

The day before Pi Day, pass out paper plates, and assign each student a digit. Have them draw the number on the plate, and color and decorate it. On Pi Day, hang them along a string or on the hallway wall, or have everyone hold their plate and stand in one big circle.

» At Foothill Knolls Elem. in Ontario, CA, a square of more than 200 students was formed outside the building, each one holding his or her decorated paper plate. “We wanted to do just more than tell them about it,” said sixth grade teacher Beth Stone. “This allows them to actually become a part of Pi.”

Make a chain of beads, where each number is represented by a different color. Students can make personal bracelets, or work on one ultra-long strand as a class.

» Greenway School students in Knoxville, TN worked to assemble a string of 4,000 beads.

Bake small bread loaf-style cakes, and frost each one with five digits of pi. Line them up, and dig in.

» One school in Spokane, WA ate 150 digits this way!

Hold an instant-memory challenge for those who haven’t learned any of the number by heart. Ask for a student volunteer. As in the “Simon” game, have the student parrot back the number after you say it, adding one more digit each time, until they make a mistake.

» You: “3.1415926.” Student: “3.141595…6?” You: “Oops! Nice job, you made it six digits. Next!”
» Your class will be shocked as to how many digits they all know, after five or ten of them take the challenge.

Have each student write one digit of pi on a note card, and staple them in order as you hang them down the math hallway.

» Twelve hundred students at Red River H.S. in Grand Forks, ND stapled 1,200 cards into an 80-foot Pi Day banner.