An irrational number is a number that cannot be written as a fraction. When written in decimal form, irrational numbers have an infinite number of decimal places which do not repeat.
π is the ratio of a circle's circumference to its diameter. This concept is important to construction and has been used for at least 4 thousand years.
π is often approximated to 22/7, but this fraction is only accurate to 2 decimal places. The ancient Egyptians and Babylonians approximated π to 25/8, which is accurate to only 1 decimal place.
The cache is a small 1/2 litre tupperware box.
It contains an ink pad and rubber stamp to commemorate the Thank God It's Pi Day event, held on 3.14.15. These are not to be removed from the cache!