From schoolkids learning about constant numbers to pizza deals to school serious math equations, here’s a slice of Pi Day fun ...

But come March 14, it is all about paying due to perfect pies, for that is Pi Day. The date tells the tale: It's 3/14, or ...

On March 14, math classes across the country will celebrate Pi Day—a national holiday in honor of the mathematical constant pi, which represents the ratio of a circle’s circumference to its diameter ...