Discovering Pi Through Explorations

Objects to be Measured:


Use the string and ruler to measure the circumference of the tops of the objects. To do this, first wrap the string around the object.  Mark where the string meets itself.  Measure this length with the ruler.  Once you are done with that, measure the length of each diameter.

List these measurements in a table like the one below:

Pop Can

Soup Can

Juice Can

Garbage Can

Coffee Can

How does the circumferece compare to the diameter?  Is it twice as big?  Three times as big?
In the column marked "Comparison", list the ratio of the circumference to the diameter.  To find
this ratio, simply divide the circumference by the diameter.  This comparison ratio is called Pi.


Round all of your ratios to the nearest hundereth.
Compare your ratios to those listed in the Discovery Table on the Main Page .

The number most commonly used to represent Pi is 3.14
How do the values of Pi you have discovered compare?
Was your calculation Greater or Less than 3.14?

Are your values of Pi consistent?
If so, what can account for the consistency?
If not, what can accound for the differences?