COEUR d’ALENE — Nothing beats a nice, warm slice of 3.14159...

AKA, pi (p).

The time to celebrate this mathematically magnificent number is annually March 14, International Pi Day, which is Tuesday.

Gizmo-CDA will host Pi Day festivities from 5-7 p.m. for parents and kids to participate in pi and pie activities — memorize as many of pi's one trillion digits as possible, win prizes for reciting the most pi digits, enter the homemade pie contest, see what projects are being done with a Raspberry Pi computer and eat free pizza pie compliments of Capone's.

Why would anyone want to celebrate this mathematical constant that allows for the calculation of area inside a circle?

"As unlikely as it may seem, the number Pi, 3.14159 ... has been crucial to the development of modern life," reads a press release from Gizmo.

Dating back to ancient Babylon and Egypt, Pi approximations were used to manage flooding of the Tigris, Nile and Euphrates rivers, for astronomy and for surveying and building.

The ancient Greeks were the first to study Pi for its own mathematical sake.

"Without pi, there is no theory of motion and no understanding of geometry," the release states. "For instance, the volume of a sphere of radius r is 4/3pr3 and that of a cylinder of height h is pr2h. Pi occurs in important fields of applied mathematics. It is used throughout engineering, science and medicine and is studied for its own sake in number theory."

The Pi Day celebration is free and will take place in Gizmo-CDA, 806 N. Fourth St., Coeur d'Alene.

Info: 651-6200