Today is March 14th, celebrated as National Pi Day. This day honors the mathematical constant 3.14, which represents the ratio of a circle's circumference to its diameter.

Years ago, the infinite decimal 3.14 or its Greek symbol pi was mostly known to math and science geeks, but now March 14 is also a day for tasty deals. Here’s a little history to whet the appetite. The first “Pi Day” celebration was held in San Francisco in 1988 when a physicist at the Exploratorium,