WEST PALM BEACH, Fla. (AP) — Math enthusiasts around the world, from college students to rocket scientists, celebrate Pi Day, which is March 14 or 3/14 — the first three digits of an infinite number with many practical uses. Many people will mark the day with a slice of pie — sweet, savory or even pizza.

Pi, which is the ratio of a circle's circumference to its diameter, is celebrated with its own holiday on March 14.

Pi belongs to a huge mathematical group called irrational numbers, which go on forever and cannot be written as fractions. Scientists have calculated pi to 105 trillion digits, although most of us are more familiar with the approximation 3.14. But how do we know that pi is an irrational number?

Pi Day, March 14th, when the date reads 3.14, might just be one of my favorite national food days. Personally, I'm not a "math person," but I am a baker who is never going to pass up an opportunity to celebrate with pie.