Pi is the most studied number in mathematics, and for good reason. The number pi is integral to our understanding of geometry. Pi has uses in physics, astronomy, and mathematics. Pi is used in architecture and construction as well, and has been a vital part of everything from arches and bridges to the Pyramids of Giza.

**Here are 25 fascinating facts about pi:**

**1.** The symbol for Pi has been in use for over 250 years. The symbol was introduced by William Jones, a Welsh mathematician, in 1706. The symbol was made popular by the mathematician Leonhard Euler.

**2.** Since the exact value of pi can never be calculated, we can never find the accurate area or circumference of a circle.

**3.** March 14 or 3/14 is celebrated as pi day because 3.14 are the first digits of pi. Math nerds around the world love celebrating this infinitely long, never-ending number.

**4.** The record for reciting the most number of decimal places of Pi was achieved by Rajveer Meena at VIT University, Vellore, India on 21 March 2015. He was able to recite 70,000 decimal places. To maintain the sanctity of the record, Rajveer wore a blindfold throughout the duration of his recall, which took an astonishing 10 hours! Can’t believe it? Well, here is the evidence.

**5.** Pi is actually a part of Egyptian mythology. People in Egypt believed that the pyramids of Giza were built on the principles of pi. The vertical height of the pyramids have the same relationship with the perimeter of their base as the relationship between a circle’s radius and its circumference. The pyramids are phenomenal structures and are one of the seven wonders of the world.

**6.** Physicist Larry Shaw started celebrating 14 March as Pi day at San Francisco’s Exploratorium science museum. There he is known as the Prince of Pi.

**7.** There is an entire language made from the number Pi. But how is that possible? Well, some people loved pi enough to invent a dialect based on it. In “Pi-lish” the number of letters in each word match the corresponding digit of pi. This first word has three letters, the second has one letter, the third has four letters, and so on. This language is more popular than you might think. Software engineer Michael Keith wrote an entire book, called *Not a Wake*in this language.

**8.** Pi wasn’t always known as pi. Before the 1700s, people referred to the number we know as pi as “the quantity which when the diameter is multiplied by it, yields the circumference”. Not surprisingly, people got tired of saying so much whenever they wanted to talk about Pi. The Welsh mathematician William Jones, a friend of Sir Isaac Newton, began using the symbol for pi in 1706.

**9.** We will never be able to find all the digits of pi because of its very definition as an irrational number. Babylonian civilization used the fraction 3 ⅛, the Chinese used the integer 3. By 1665, Isaac Newton calculated pi to 16 decimal places. Computers hadn’t been invented yet, so this was a pretty big deal. In the early 1700s Thomas Lagney calculated 127 decimal places of pi, reaching a new record. In the second half of the twentieth century, the number of digits of pi increased from about 2000 to 500,000 on the CDC 6600, one of the first computers ever made. This record was broken again in 2017 when a Swiss scientist computed more than 22 trillion digits of pi. The calculation took over a hundred days.

**10.** The usefulness of pi has been a matter of debate, although it is loved by a lot of math enthusiasts. Some believe that tau (which amounts to 2π) is a better suited to circle calculations. For instance, you can multiply tau with the radius of a to calculate its circumference more intuitively. Tau/4 also represents the angle of a quarter of a circle.

**11.** In the Exploratorium science museum, a circular parade happens every year on pi day. Each person participating holds one digit in the number pi. It wasn’t celebrated around the United States like it is now until Congress passed Resolution 224, which designated March 14th as pi day. Congress hoped that celebrating pi day would cultivate a higher level of enthusiasm for math and science among American students.

**12.** The calculation of pi is a stress test for a computer. It works just like a digital cardiogram since it indicates the level of activity within the computer’s processor.

**13.** Givenchy sells a men’s cologne with the name ‘Pi’. The company markets this product as capable of enhancing the attractiveness of intelligent and visionary men.

**14.** The number pi is not just an important part of conversations among mathematicians or students. In the famous O.J. Simpson trial, the defense attorney and FBI agent’s argument revolved around the value of pi. The FBI agent’s findings in the case weren’t accurate because he used pi inaccurately.

**15.** The number pi was so alluring, even in the 16th century, that Dutch-German mathematician Ludolph van Ceulen spent most of his life calculating the first 36 digits of pi. It is said that the first 36 numbers were engraved on his tombstone, which is now lost.

**16.** William Shanks, a British mathematician, worked manually to find the digits of pi in 1873. He spent many years trying to calculate the pi digits by hand and found the first 707 digits. Unfortunately, the 527th digit he found was wrong, which made all the following digits wrong as well.

**17.** In the year 1888, an Indiana country doctor claimed that he had learned the exact measure of a circle through supernatural means. He believed in his “supernatural” knowledge so much that he filed a proposal to pass a bill in the Indiana legislature so that he could copyright his genius findings. However, there was a math professor in the legislature who showed the fellow how his proposed bill would result in a wrong value of pi.

**18.** The number pi is literally infinitely long. But the number 123456 doesn’t appear anywhere in the first million digits of pi. It is a bit shocking because if a million digits of pi don’t have the sequence 124356, it definitely is the most unique number.

**19.** Chinese people were far ahead of the West in finding the digits of pi. Why? Chinese mathematicians were ahead in the pi game because of two reasons: they had decimal notations and they had a symbol for the number zero. It wasn’t until the late middle ages that European mathematicians started using the number zero. At that time, European mathematicians partnered with Arab and Indian minds to bring the symbol of zero into their system.

**20.** In ancient times, mathematicians used a unique method to calculate pi. They would add more and more sides to a polygon so that its area approached the area of a circle. Archimedes, the most famous Greek mathematician and inventor, used a polygon with 96 sides. Many other mathematicians also used this polygon-method to compute the infinitely long number pi. In China, a mathematician used over 3,000 sides in a polygon to arrive at the value 3.14159. Another mathematician used about 25,000 sides to calculate pi.

**21.** Many mathematicians believe that it is more accurate to say that a circle has infinite corners than it is to say that it has none. It is only reasonable to assume that the infinite number of corners in a circle correlates to the infinite number of digits of pi.

**22.** The number pi is very effective when you used in calculations For instance, rounding the number pi to just 9 digits after the decimal and use it to calculate earth’s circumference yield incredibly accurate results. For every 25,000 miles, the number pi will only err to 1/4th of an inch.

**23.** Even today, people are racing to calculate more digits of pi in a never ending competition. In the year 2010, a Japanese engineer and an American computer wizard broke the record for the most number of pi digits by calculating up to 5 trillion digits of pi. The amazing part is that they didn’t use any supercomputers. They just used desktop computers, 20 external hard disks, and their brilliant minds.

**24.** The Greek letter π is the first letter of the word periphery and perimeter. And as we all know, pi is the ratio of a circle’s “periphery” to its diameter.

**25.** Interestingly, some of the most famous scientists in the world have a connection to pi day. Albert Einstein was born on March 14th, 1879. Stephen Hawking died on March 15th, 2018 at the age of 76.

## FAQs

### What are some fun facts about Pi Day? ›

**The Pi symbol was introduced by William Jones, a Welsh mathematician, in 1706**. In 1737, Leonhard Euler popularised the usage of the symbol. Pi Day was celebrated for the first time in 1988 by American physicist Larry Shaw. The value of Pi was determined till a record-breaking 22 trillion decimal places in 2017.

**What is so unique about pi? ›**

Regardless of the circle's size, this ratio will always equal pi. In decimal form, the value of pi is approximately 3.14. But **pi is an irrational number, meaning that its decimal form neither ends (like 1/4 = 0.25) nor becomes repetitive** (like 1/6 = 0.166666...).

**Who invented Pi Day? ›**

March 14 marks Pi Day, an annual celebration of the mathematical sign pi. Founded in 1988 by physicist **Larry Shaw**, March 14 was selected because the numerical date (3.14) represents the first three digits of pi, and it also happens to be Albert Einstein's birthday.

**Who was born on Pi Day? ›**

**Albert Einstein's** birthday is on March 14 — 3/14 — which is celebrated as Pi Day.

**Why is pi called pi? ›**

And how did it get the name "pi"? It was first called "pi" in 1706 by [the Welsh mathematician] William Jones, because **pi is the first letter in the Greek word perimitros, which means "perimeter."**

**Why is Pi so important? ›**

The constant π **helps us understand our universe with greater clarity**. The definition of π inspired a new notion of the measurement of angles, a new unit of measurement. This important angle measure is known as “radian measure” and gave rise to many important insights in our physical world.

**Does pi have a limit? ›**

Fractions such as 22/7 and 355/113 are commonly used to approximate π, but no common fraction (ratio of whole numbers) can be its exact value. Because π is irrational, **it has an infinite number of digits in its decimal representation**, and does not settle into an infinitely repeating pattern of digits.

**How is π used in daily life? ›**

In basic mathematics, Pi is used to find area and circumference of a circle. You might not use it yourself every day, but **Pi is used in most calculations for building and construction, quantum physics, communications, music theory, medical procedures, air travel, and space flight**, to name a few.

**How far has pi been calculated? ›**

Then, in 2021, scientists at the University of Applied Sciences of the Grisons calculated another 31.4 trillion digits of the constant, bringing the total up to **62.8 trillion decimal places**. Today we're announcing yet another record: 100 trillion digits of π.

**How did we find pi? ›**

The first rigorous approach to finding the true value of pi was **based on geometrical approximations**. Around 250 B.C., the Greek mathematician Archimedes drew polygons both around the outside and within the interior of circles. Measuring the perimeters of those gave upper and lower bounds of the range containing pi.

### Why is pi invented? ›

Oughtred used π to represent the circumference of a given circle, so that his π varied according to the circle's diameter, rather than representing the constant we know today. The circumference of a circle was known in those days as the 'periphery', hence the Greek equivalent 'π' of our letter 'π'.

**Why pi is the most mysterious number? ›**

Simply put, pi is weird. Mathematicians call it a "transcendental number" because **its value cannot be calculated by any combination of addition, subtraction, multiplication, division, and square root extraction**.

**What is the mystery of pi? ›**

**Pi is a never-ending number**

It can't be expressed as a fraction; it doesn't end with a repeating pattern (like the decimal expression of 1/3, 0.33333…, in which the threes repeat forever), or terminate after a certain number of decimal places (like 3/4, or . 75). It just keeps going, going, and going.

**What pi means? ›**

The abbreviation "P.I." stands for "Principal Investigator" and is routinely used in the United States to denote a "head of the laboratory" or "research group leader" (wikipedia), and serves to refer to active researchers with potential funding for PhD students or post-doctoral researchers.

**When was first Pi Day? ›**

The idea of "Pi Day" originated with physicist Larry Shaw, who organized the first Pi Day celebration at the San Francisco Exploratorium in 1988. Almost exactly twenty-one years later, on March 11, 2009, the U.S. House of Representatives passed a resolution proclaiming **March 14** to be National Pi Day.

**Who died on Pi Day? ›**

Later known for his crazy hair, **Einstein** rocked the science world with his theory of relativity and his oft-quoted E = mc2 equation. The physicist died on April 18, 1955, but only after making a lasting impression on the world.

**Is there a 0 in pi? ›**

**The first zero in pi occurs at position 32**. What is the probability of a digit not occurring in 32 or greater randomly chosen digits?

**What is the first number in pi? ›**

The first 100 digits of pi are **3.1415926535 8979323846 2643383279 5028841971 6939937510 5820974944 5923078164 0628620899 8628034825 3421170679**. The value of pi starts with a 3 followed by a decimal point.

**What is the Colour of pi? ›**

Remember that Pi has already associated the color **orange** positively with the Hindu religion.

**What is the first 1000000000000 digits of pi? ›**

**3.1415926535 8979323846 2643383279 5028841971 6939937510 5820974944 5923078164 0628620899 8628034825 3421170679** …

### Does pi exist in nature? ›

Did You Know? **Pi appears in every circle, including those found in the natural world**. Pi, also written as the symbol π, is the ratio of a circle's circumference (distance around a circle) to its diameter (distance across a circle passing through the center).

**Is there a pattern in pi? ›**

We have known since the 18th century that we will never be able to calculate all the digits of pi because **it is an irrational number, one that continues forever without any repeating pattern**.

**What is 2 pi called? ›**

Pi (π) still equals the same infinite string of never-repeating digits. Rather, according to The Tau Manifesto, "pi is a confusing and unnatural choice for the circle constant." Far more relevant, according to the algebraic apostates, is 2π, aka **tau**.

**What is the history of pi? ›**

pi, in mathematics, the ratio of the circumference of a circle to its diameter. The symbol π was devised by British mathematician William Jones in 1706 to represent the ratio and was later popularized by Swiss mathematician Leonhard Euler.

**How do you calculate pi without a calculator? ›**

Calculate Pi WITHOUT a Ruler! - YouTube

**Does NASA use pi? ›**

**Engineers use pi to put spacecraft into orbit around other planets**. To do this, they have to slow down the spacecraft just enough and at exactly the right time for it to get pulled into orbit by the planet's gravity.

**How is pi used in medicine? ›**

**The person(s) in charge of a clinical trial or a scientific research grant**. The PI prepares and carries out the clinical trial protocol (plan for the study) or research paid for by the grant. The PI also analyzes the data and reports the results of the trial or grant research. Also called principal investigator.

**How is pi used in air travel? ›**

Pi has a big role to play in actuation. **Actuators control the flaps that move on aircraft wings and tails or the parts that open and close valves on jet engines**. Controllers send signals to electric motors, telling them how fast they need to spin to make the actuators move, said Terry Ahrendt, a systems engineer.

**Does pi have a limit? ›**

Fractions such as 22/7 and 355/113 are commonly used to approximate π, but no common fraction (ratio of whole numbers) can be its exact value. Because π is irrational, **it has an infinite number of digits in its decimal representation**, and does not settle into an infinitely repeating pattern of digits.

**How many pi digits are known? ›**

Then, in 2021, scientists at the University of Applied Sciences of the Grisons calculated another 31.4 trillion digits of the constant, bringing the total up to **62.8 trillion** decimal places.

### Why is Pi so important? ›

In basic mathematics, pi is used **to find the area and circumference of a circle**. Pi can be used to find an area by multiplying the radius of the circle squared times pi. So, to find the area of a circle with a radius of 3 centimeters, the calculation would be π3^2 = 28.27 cm.

**What is the mystery behind pi? ›**

**Pi is a never-ending number**

It can't be expressed as a fraction; it doesn't end with a repeating pattern (like the decimal expression of 1/3, 0.33333…, in which the threes repeat forever), or terminate after a certain number of decimal places (like 3/4, or . 75). It just keeps going, going, and going.

**What is 2 pi called? ›**

Pi (π) still equals the same infinite string of never-repeating digits. Rather, according to The Tau Manifesto, "pi is a confusing and unnatural choice for the circle constant." Far more relevant, according to the algebraic apostates, is 2π, aka **tau**.

**What is the exact number of pi? ›**

The value of Pi (π) is the ratio of the circumference of a circle to its diameter and is approximately equal to 3.14159. In a circle, if you divide the circumference (is the total distance around the circle) by the diameter, you will get exactly the same number.

**How is pi calculated? ›**

What is the Pi Formula? The formula for the value of pi is the ratio of the circumference of a circle to its diameter. In the ratio form, it is represented as π = Circumference/Diameter.

**Who is father of pi? ›**

The first calculation of π was done by **Archimedes of Syracuse** (287–212 BC), one of the greatest mathematicians of the ancient world.

**What is the 100 trillionth digit of pi? ›**

The 100-trillionth decimal place of π (pi) is **0**.

**What is the last number in pi? ›**

Humans have now calculated the never-ending number to 31,415,926,535,897 (get it?) — about **31.4 trillion** — decimal places.

**How do we use PI in everyday life? ›**

In basic mathematics, Pi is used to find area and circumference of a circle. You might not use it yourself every day, but **Pi is used in most calculations for building and construction, quantum physics, communications, music theory, medical procedures, air travel, and space flight**, to name a few.

**What is pi used for today? ›**

For example, it can be used to calculate a circle's circumference (π times diameter), or its area: A=πr^{2} — how I keep this formula lodged in my neurons is using the “all pies are square” trick. It's also used in calculating various elements of the sphere, such as its volume (4/3πr^{3}) or surface area (4πr²).

### What is the first 1000000000000 digits of pi? ›

**3.1415926535 8979323846 2643383279 5028841971 6939937510 5820974944 5923078164 0628620899 8628034825 3421170679** …

**What's the most mysterious number? ›**

Simply put, **pi** is weird. Mathematicians call it a "transcendental number" because its value cannot be calculated by any combination of addition, subtraction, multiplication, division, and square root extraction. In this delightful layperson's introduction to one of math's most interesting phenomena, Drs.

**Does pi exist in nature? ›**

Did You Know? **Pi appears in every circle, including those found in the natural world**. Pi, also written as the symbol π, is the ratio of a circle's circumference (distance around a circle) to its diameter (distance across a circle passing through the center).

**What is pi for kids? ›**

π - Math for Kids - What is Number Pi? - YouTube