National Pi Day

Delightful twist of math and pastries! Young person holding a pie, wearing a nerdy t-shirt, surrounded by math equations on a chalkboard..
National pi day illustration

Are you a number geek? Or just a pie lover? Well, National Pi Day may just be your new favourite day. A delightful twist of math and pastries all rolled into a 24-hour celebration on the 14th of March.

When is Pi Day?

It's national pi day on the 14th March.

What is National Pi Day?

National Pi Day is, quite deceptively, not about an affinity towards delicious baked goods. Rather, this celebration revolves around the mathematical constant known as Pi (π). This fun-filled day is celebrated on the 14th of March each year, aptly in recognition of 3.14 - the value of Pi rounded to two decimal places.

A Little Pi in The Virtual Sky

In our online era, National Pi Day has found a home within the vast world wide web. With 19055 mentions of National Pi Day found online, it's clear that this joyous day has garnered a considerable following. It reached a digital pinnacle on the 14th of March, 2017, with internet users expressing their love for this irrational figure at an all-time high.

Why Celebrate Pi?

While it may seem odd to dedicated an entire day to a mathematical constant, Pi is actually a fascinating figure. It's used in a variety of mathematical equations, including those relating to circles and spherical objects. In a metaphorical sense, Pi is an apt symbol for our interconnected and continuously expanding digital world, represented by the path of electronic circuits and satellite trajectories to our round-earth model.

Indulge in a Slice of Tradition

Of course, it's hard to ignore the tantalizing pun nestled in the heart of National Pi Day. Many celebrate not only with math equations, but with mouthfuls of delicious pies. After all, who doesn't love a tasty and educational national day?

History behind the term 'Pi'

250 BCE

Ancient Greece: The Birth of Pi

The concept of pi, often represented by the Greek letter π, can be traced back to ancient Greece. The mathematician Archimedes of Syracuse is said to have been the first to rigorously explore the properties of pi around 250 BCE. Although the exact value of pi was not calculated, Archimedes provided an approximation by inscribing and circumscribing polygons around a circle.

16th Century

The Term 'Pi' is Coined

The term 'pi' was first introduced by the Welsh mathematician William Jones in the 16th century. Jones chose the Greek letter π as a shorthand for 'periphery,' as he believed that the ratio of a circle's circumference to its diameter represented the periphery of the circle. This notation gained popularity over time and is now universally recognized as the symbol for this mathematical constant.


The Use of π by Leonard Euler

In 1706, the renowned Swiss mathematician Leonard Euler began using the symbol π in his works. Euler's prolific contributions to mathematics helped popularize the use of π and solidify its significance. His usage extended beyond circles to various mathematical formulas and series, making π an integral part of advanced mathematical concepts.


The Adoption of π as a Mathematical Constant

The Scottish mathematician William Hamilton was a key proponent in the formal adoption of π as a mathematical constant in 1768. He emphasized that π is not limited to calculations involving circles but has widespread usefulness in mathematics as it appears in numerous formulas, calculations, and branches of study. Hamilton's efforts helped establish π as an irreplaceable constant in mathematical literature.


The Symbol π is First Encountered in American Literature

The symbol π made its initial appearance in American literature in 1873. The mathematician and educator Charles Lutwidge Dodgson, better known as Lewis Carroll, used the symbol in his book 'Through the Looking-Glass' when describing mathematical puzzles. This literary inclusion contributed to further recognition and general understanding of π among the wider public.

20th Century

Increased Computation Accuracy of π

With the advent of computers, mathematicians and computer scientists focused on the precise calculation of π. In the 20th century, significant advancements were made in computing π to millions and billions of decimal places. These computational achievements expanded the knowledge of π's digits and sparked fascination among mathematicians, leading to various record-breaking calculations.


The First π Day Celebration

In 1988, π Day was first celebrated by physicist Larry Shaw and his colleagues at the San Francisco Exploratorium. They chose March 14th (3/14) as the date to honor the numerical approximation of π, 3.14. Since then, π Day has gained popularity worldwide, with enthusiasts engaging in π-related activities, recitation contests, baking pies, and appreciating the beauty of this mathematical constant.

Did you know?

Pi has been calculated to over one trillion digits beyond its decimal point. However, for most calculations, just the first 3 or 4 digits are used.


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First identified

8th March 2015

Most mentioned on

14th March 2017

Total mentions


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