Pi Day plays off the fact that March 14 – 3/14 – is a numerical pun on math’s best-known irrational number: pi, or 3.14. But there’s nothing irrational about punning pi, the ratio of a circle’s circumference to its diameter, with pastry as well.
The day has come to be known as a celebration of pie as well as pi (and, coincidentally, Albert Einstein’s birthday). In Seattle, pie tends to trump pi.
