# Pi, Pi, Mathematical Pi

Every day this week we took a look at Pi.  On Monday and again later in the week we listened to the Mathematical Pi Song (to the tune of American Pie). I gave each student a paper plate and assigned them a number.  They were to write that number on the plate and decorate.  We hung the plates in a “Pi Number Line” down the hall.  That way we could think about this irrational number all week!  I gave each student a copy of the Greek Alphabet and we practiced reciting it.  I wanted them to see the letter Π and know where it came from.

On Tuesday we reviewed the words <radius>, <circumference>, and <diameter>.  Earlier in the year we had discovered that the word sum for <circumference> is  <circum> + <fer> + <ence>.  The prefix <circum> means around and the base <fer> means to carry.  The circumference is the distance carried around the outside of the circle.  The word sum for <diameter> is <dia> + <meter>.  The prefix <dia> means through and the base <meter> means to measure.  You measure the distance through the circle to find the diameter.    The word sum for <radius> is <radi> + <us>.  The base <radi> means rod, spoke of wheel, and ray of light.  I like to picture the radius of a circle as a spoke of a wheel.  I brought miniature donuts.  We multiplied the diameter of a donut by Pi, and in doing so calculated the circumference of the donut.  We watched another video having to do with Pi.  This one was the  ‘The Dance of the Sugar Pi Fairy’!  How fun to find creative ways to memorize digits of Pi.  (Certainly not a necessary thing to do, but certainly a tempting thing to do)

On Wednesday I brought cookies.  We measured the circumference and divided that by Pi to calculate the diameter of the cookie.  We also listened to some very creative math/musicians who put digits of Pi to music!  The first one is called Song from Π.  It is an enchanting piano piece with interesting facts about the number Pi.  The digits of Pi float by as they are being played on the piano.  Quite honestly, we loved the music, but found it difficult to follow the digits.  The second one was fascinating for other reasons.  The artist repeats the first 31 digits of Pi.  He uses different instruments and different tempos.  It’s called What Pi Sounds Like.

On Thursday I brought peanut butter cups and we measured both the circumference and the diameter.  We then found Pi by dividing the circumference by the diameter.  Several students came up with 3.166.  That’s pretty close!  We watched a video about art created from the digits of Pi.  It is called Pi is Beautiful.   We were inspired to see what kind of art we could create using the digits of Pi.  I found a circular graph.  We numbered around the outside using the digits of Pi.  If the number was a 3, then 3 squares toward the center were colored in.  Some students assigned a specific color to each number 1-9 to see what that would look like.  Some students stuck to using 1, 2, or 3 colors.  We were very pleased with the results and hung them in the hall above our Pi number line.

Then came Friday – March 14!  Students brought in pies – 17 in all!  We ate pie several times throughout the day and shared with adults around the school.  We held a contest to see who had been able to memorize the most digits of Pi throughout the week.  Our winner memorized 100 digits of Pi!  We were amazed!  Our second place winner memorized 61 digits and our third place winner memorized 24 digits!  Wow!  What fun.  Enjoy the following video.  It’s kind of a medley of our day!

# Celebrating Pi Day with Pizazz!

Pi.  Pi.  Mathematical Pi!   We had so much fun today!  We sang songs.  Some were based on familiar Christmas tunes, one was a rap, and one went to the tune of American Pie.  We learned about William Jones who first recorded the symbol for Pi.  We  read about Gaurav Raja who at one time held the record for reciting 10,000 digits of Pi.  We learned about Ludoph van Ceulen who had the first 35 digits of Pi engraved on his tombstone (until his wife swapped it out for something more proper)!

We felt that in order to really understand Pi, we needed to really understand circumference, diameter, and radius.  The class divided into three groups and the word investigations began!  With limited time, no group quite finished, but they made great progress.  I find it interesting that many students still fall back on old habits of dividing words by syllables instead of beginning with their lists of tried and true affixes.  Patience and practice.  They must discover the logic of that for themselves.   In one part of the video, the group investigating the word <diameter> started laughing.  I had just asked if the words they found that begin with <dia> had to do with the definition of <dia> which is through.  You see, diarrhea was on the list and they definitely saw the connection!

Next we held a Pi Digit Contest.  We were looking to see who could memorize the most digits of Pi with only two days of preparation.  Our first place winner recited 65 Pi digits!  In second and third place, students recited 46 and 42 places respectively.  The fourth, fifth, and sixth place winners recited 36, 28, and 27 places.  What an amazing accomplishment for all who gave it a try!

Then there were the pies!  Yum!  We had cherry, lemon meringue, apple, turtle, peanut butter, chocolate, toasted coconut creme, pecan, banana creme, and brownie pies.  Heavenly!

During math, we actually measured circles of all kinds and calculated Pi for ourselves by dividing the circumference by the radius.

Lastly, we sang our favorite Pi song just one more time.  Love Pi Day!