Pi Day (Week) Math Lessons     



Activity 1 - Read Sir Cumference and the Dragon of Pi.  Stop at page 15 and do DISCOVERING PI ACTIVITY.  After completing DISCOVERING PI, finish reading Sir Cumference and the Dragon of Pi.


Discovering Pi 


Using a tape measure (centimeter side), measure the circumference and diameter of 6 different objects.  Measure to the nearest ½ centimeter.  Record the object number, circumference, and diameter in the chart below.  Then, write the ratio of the circumference to the diameter in the form of a fraction.  Next, use a calculator to change the fraction into decimal form, rounding to the nearest thousandth.  After doing this for all 6 objects, find the mean (average) of the 6 calculations.


Lid #









divided by Diameter
































                                                        Average ___________


Explain what pattern developed when you divide the circumference by the diameter?



A commonly used approximate for pi is 3.14.  How close is your average to pi ?  Find the difference between your average and pi.


Writing Prompts for Discovering Pi


1.      In mathematics, Pi is approximately 3.14159.  Explain in your own words how the value for pi is found.


2.     Pi is an irrational number.

a)  Write 2 or more sentences explaining what it means for a number to be irrational.

b)  Give an example of a number that is rational and write a sentence explaining why it is rational.


3      Which approximate is more accurate for pi:  22/7   or 3.1?  Explain why. Use complete sentences.



Activity 2 – FAVORITE PIE GRAPHS.  This activity takes about 60 minutes.  Have students vote for their favorite type of pie.  Find the percent of the class that voted for each type of pie.  Calculate the percent of 360 degrees for each “slice”.  Have the students make a PIE GRAPH of the results.  Make the graph inside of a pie tin.






Favorite Pie Data







Percent of 360

































































































































Activity 3 – Complete the PI DAY SCAVENGER HUNT.  http://www.expage.com/piinfo

Pi Day Internet Scavenger Hunt


Math Glossaries

1)  What is the circumference of a circle?


2)  What is the diameter of a circle?


The Story of Pi

3)  What is PI the ratio of?


4)  What value of PI did the Egyptians obtain 2000 years before Christ?


5)  What value of PI did the Babylonians obtain?


6)  Where in the Bible is there an indication of the value of PI?


     What was this approximate value?


7) Which fraction is closest to the actual value of PI…..

          337/120      or      22/7  or      355/113  ?

    What is the decimal equivalent of it (to 8 decimal places)?


8) What does it mean to “square a circle”?



Birthday in Pi

9)  Find your birthday in PI.  Type in your date of birth and record the location.


Joy of Pi

10) In the year 1997, D. Takahasi and Y. Kanada calculated PI to 51,539,600,000 decimal places.  What type of computer did they use? 

Where did they do the calculation?


Planet Pi

11)  Is PI a rational or irrational number?  Explain why.


12)  What is PI to 30 decimal places?


13) What is the symbol for pi?             Who first used it and when?

     What Swiss mathematician was it popularized by?


Web Page Dedicated to Pi

14) Who were the first people known to find a value for pi?        

     When was it?


15) In the first one million digits of pi, how many threes are there?

     How many nines?


16) People once thought that trying to square a circle was an illness.  What was the name of the illness?


17) What was the most inaccurate version of PI?  Explain who, when, and what the value was?


18) Who memorized 42,195 digits of PI on Feb. 18, 1995?  Where was the person from?


Online Dictionary

19) You can memorize PI by using things called “mnemonics”  What is a “mnemonic?


Activity 4 – Draw a picture of a circle with different parts labeled (diameter, radius, chord, arc, etc).  Answer questions about what each of them is and the relationships among them.  Find this information on the Internet. 




Go to the Math.com website.  Scroll down until you see the picture of the circle.  Below the circle are the words radius, chord, diameter, arc, and semi-circle.  Click on each (one at a time) then label the parts on the circle below.












Go to the bottom of the page and click NEXT.  Use the information of that page to answer the following questions.

1)       What is perhaps the “most seen” shape?


2)      By definition, what is a circle?


3)      If a plate is not a circle, what is it?               What part of the plate is a circle?


4)      What is a circle name by?


5)      What is the plural of “radius?


6)      What is the relationship between diameter and radius?


7)      What is a “chord”?


8)      How many degrees does a circle contain?


9)      Define:        minor arc:

                             major arc:

                             semi circle:


10)     What is the circumference of a circle?


11)      What are concentric circles?


12)     When you slice a round pizza, you usually slice along a ___________?


13)     What is the name of the tool used to construct circles?




Go to Math Goodies.com website to answer the following questions.



1)       The distance around a circle is the _____________.


2)      What is pi the ratio of?


3)      How is the relationship between diameter and radius expressed?


4)      What is the formula for area of a circle?


Activity 5 – Have the students make a criss-cross puzzle or word search puzzle using pi and circle related words at http://www.discoveryschool.com/puzzlemaker .


Activity 6 – Make a PI CHAIN.  Use 10 different colors of construction paper, one for each digit 0 – 9.  Give each student 10 digits of pi to make the chain for, using the colored paper to represent the digits.  For example, if 1=red, 2=blue, 3=green, 4=yellow, etc…, 3.141 would be green, then red, then yellow, then red.  Connect the 10 digit chains together to form a long PI CHAIN.  See http://www.mathwithmrherte.com for more information.




Directions for Pi Chain

1)       Get the next 10 digits of pi.

2)       Select the colors you need for the digits.

3)       Cut strips of paper 9inches by 1.5 inches.

4)       Connect the colored strips in the order of the digits.

5)       Do NOT glue the last link.  Paper clip it together and attach the paper with your digits of pi. 

6)       Your chain will be connected to the previous 10 digits and the next 10 digits of pi. (That is why you don’t glue the last link, so it can be connected to the next 10 digits of pi.)




Activity 7 – Show the video GOING AROUND IN CIRCLES.  Have the students answer the questions as they watch the movie.





Video - Going Around in Circles


1)         A curve is line that is constantly changing its __________.


2)         A flexible line hanging from 2 supports is called a __________ curve.


3)         Name 2 types of curves in a roller coaster.  __________ ________.


5)         Why were roller coasters redesigned from loop-to-loops to teardrops?


4)         What is the distance from the center of a circle to the edge of a circle, that is the fixed distance from the center called? _________


6)         Part of a circle is called an ______?


7)         How many degrees in a circle? _________


8)         The distance around a circle is the ____________ and the distance across a circle is the __________.


9)         Archimedes discovered that the circumference of a circle was a little more than _____ times the diameter.  He expressed this comparison with an approximate ratio of _____ to ______.


10)       Pi rounded to the nearest hundredth is 3._____.  What is the symbol for PI?


11)        Pi is the ratio of ______________ to _________.


12)       The formula for the circumference of a circle is C = ________.


13)       What is the approximate distance all the way around the world?


14)       A circle that fits just inside of a square has a circumference of about what fraction of the perimeter of the square? ________


15)       What shape do the 12 sections of the lemons placed together resemble?


16)       What is the formula for the area of a circle?


17)       Why are the left tires of a wing sprint car smaller than the right tires?


18)       How many days are in the moon’s cycle?



Activity 9 – Have students bring in pies to share with the class on