By Michelle Lou and Saeed Ahmed, CNN

(CNN) -- If you've been using Pi Day as an excuse to just eat pie, you're doing it wrong.

Here are some fun tidbits about pi and its day of celebration, i.e. March 14.

What is pi?

Pi is the ratio of the circumference of a circle to its diameter, or approximately 3.14.

What is Pi Day?

Pi Day occurs March 14, because the date is written as 3/14 in the United States. If you're a serious math geek, celebrate the day exactly at 1:59 a.m. or p.m. so you can reach the first six numbers of pi, 3.14159.

March 14 is also Albert Einstein's birthday.

How did Pi Day start?

Physicist Larry Shaw started Pi Day in 1988 at San Francisco's Exploratorium to celebrate the famous number and mathematics in general.

In 2009, the US House of Representatives passed a resolution to recognize Pi Day.

Who invented pi?

The mathematical concept of pi has been around for thousands of years, but it started to be known by the Greek letter only in the 1700s. Philologist William Jones began using the symbol in 1706, but it was popularized by mathematician Leonhard Euler.

Why is pi important?

Unless you're a mathematician or scientist, you probably don't encounter pi very often. But pi is essential for calculations in math, engineering, construction, physics and space exploration.

Does pi ever end?

Like our love for pie, pi is infinite. Its exact value can never be calculated, and it doesn't seem to have a pattern. Emma Haruka Iwao, a Google employee, holds the world record for calculating pi. She spent four months working on the project and calculated pi to 31.4 million digits.

Here's pi to the 10,000th digit. You should recite it.

Who holds the record for reciting pi?

Rajveer Meena holds the record for reciting the most number of decimal places of pi. In 2015, Meena recited 70,000 decimal places blindfolded. It took him 10 hours.

For more information about pi, visit www.piday.org.