Pi Day

As if you needed a reason to celebrate a mathematical concept, today is Pi Day (3/14 – get it?).  So why is this important?  (I have to use the Greek Pi, as opposed to the symbol in the blog).  There aren’t many activities here, but mostly a shout out to Pi (and those who shout out for it).

  • Pi shows the relationship between diameter and circumference of a circle.
  • Pi is a constant – no matter what size the circle, as a ratio, its value remains the same.
  • Pi is known mostly as 3.14, but it has been calculated out to over a trillion digits.
  • Pi has a long history: it comes from the Greek letters and the Egyptians used the equivalent of Pi/2 for their proportions of the pyramids – this seems to have been a good choice, if longevity plays into architecture….
  • It is central in equations for area of a circle and volume of a cylinder (central to those of us who like curling and cans of soup).
  • Is Pi a normal number?
  • Are people who wear a Pi t-shirt normal?  Lots to think about.
  • Are there any other constants that have (or should have) a day?


  1. Pi Day Website – Learn about Pi
  2. Wikipedia explanation with cool animation that actually makes the concept understandable! (This would be a great experiment to recreate.  Give students four or five circles (lids, etc) of different diameters.  Measure the diameter of each, mark a spot on the circle and roll it out, then measure the circumference (or use measuring tape).  Is the circumference 3.14 x the diameter?  Have them record their findings on a chart.


I Have Measured out My Life…

Piano_coffee_spoon“I have measured out my life with coffee spoons…”

from “the Love Song of J. Alfred Prufrock.”

A poetic math activity.

This is only one line in this poem, but one it has always striked me as one of the most powerful. There are so many ways to measure your life, to mark time, to define yourself.  (Ok, so this one isn’t as inspirational as laughs created or children saved, but to each his own or her own, right?)

For this exercise – it is very simple – identify and calculate:

How do you measure your life?

  • hours of tv?
  • texts?
  • kisses from loved one?
  • burritos?
  • ice cubes?
  • religious ceremonies?
  • cars that you’ve passed by?
  • haircuts?
  • minutes awake? (minutes asleep?)
  • books read?
  • number of innoculations?
  • great runs?
  • lines of code?

1. Identify: To start this activity, I might ask students to journal a list of activities that define them. What do your friends say about you?  What would your parents or siblings say if they were asked?

2. Estimate: Ask students to think one activity and calculate how many times they have done this.  For example – glasses of milk. If you had approximately one glass of milk per day(defined as 8 ounces) between 4 and 15 years old that would be 365 glasses of milk per year x 12 years = 4,380.  And for 0-4, maybe it is the equivalent to 3 glasses a week which would equal 624 glasses.  Total, it would be approximately 5,004 glasses of milk or 40,032 ounces.  Have students show their work to describe their choices.  Ask them to consider when this might vary and why and find ways to compensate for this in their calculation.

3. Project forward: Calculate the quantity of your life defining activity for when you are 25, 50, 80, and 95 years old.  Do you think your activity will be consistent over time? How will it vary? When? Why? How will you account for this in your estimation?


  1. Create a graph to show visually your estimation for your life from birth to age 95.
  2. What things do you expect will change the trend?  Why? How did you account for this in your calculations? Show these on the chart with specific points and explanations.
  3. Write  a paragraph analyzing your estimation. When you see this, what do you think? Is it exciting? Disturbing? Does it lead you to ask any more questions?  What do you think we should be doing more or less of as a society?  Is there anything as humans you think we should monitor and measure to aspire to do more or to do less?