Wait, There's a Pi Approximation Day to Go Along With Pi Day?

Did you know that there's a Pi Approximation Day to go along with Pi Day? They celebrate the same thing in different ways.

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Mar. 14 2024, Published 11:11 a.m. ET

Let's face it. For many of us, there's very little we remember from our old math classes that we've actually ended up using in real life. Back in middle school and high school, there were all sorts of equations and formulas that we were meant to memorize if for no other reason than to pass a few quizzes and tests. But as we grew into adults, we quickly realized how little of it actually applied to the things we ended up doing. That said, there's one constant that's probably stuck in our heads: Pi.

In technical terms, Pi is the mathematical constant that measures the ratio of a circle's circumference to its diameter. However, most of us know two things about this infamous irrational number. One of them is at least the first digit and two decimal places of 3.14. The other is that it goes on forever. Pi has been found to include an infinite number of decimal places. In fact, we even have two days to celebrate it: Pi Day and Pi Approximation Day. Wait, what's that second one?

What the heck is Pi Approximation Day? There are two days dedicated to Pi.

Not to be confused with the United States' National Pie Day which takes place on January 23, International Pi Day celebrates Pi in all of its mathematical glory. This date falls on March 14 (3/14), an obvious nod to Pi's most commonly known numerical value of 3.14. Ironically enough, some folks will celebrate by baking actual pies and decorating with the numbers or even the Greek letter that denotes it. However, you might be surprised to know that that isn't the only day that celebrates Pi.

There's also Pi Approximation Day, which falls on July 22. It isn't as widely known as the original date, but the alternative date does still have its roots in mathematics. For the sake of celebration, the numerical value of the date July 22 (7/22) is instead read as "22/7" or even "22 divided by 7."

Fun fact: 22 divided by 7 is approximately 3.14!

In other words, 22/7 offers a more-visually appealing and digestible approximation of the value of Pi. For those of us who only know Pi as 3.14, it's easier to wrap your head around this smaller form than trying to absorb all of its digits.

This is why some people (mostly mathematicians and scientists) will celebrate both Pi Day and Pi Approximation Day. They generally celebrate the same thing, but they just express it in a numerically different way.

How many digits of Pi will you be reciting on these days?