So, the today’s subject is “When is National Pi Day in 2018?” We are almost sure that we won’t hear the proper answer from you. The matter is that the reply is usually given only by mathematicians or by other people, who are dealing with this number in their profession or working sphere.

That is an explanation, why we want to tell you about this interesting, but at the same time rather unknown special occasion.

## History

Certainly, it would be quite silly to investigate the subject, what day World Pi Day in 2018 is, without discovering the past of this event.

Mathematics is a very interesting and entertaining science, a special place in which the calculation of the number Pi takes place. *The history of its calculation takes more than 2,000 years, and the accuracy of the calculation ranges from 256/81 in ancient Egypt and 339/108 in the Vedas, to Jamshid al-Kashi, who calculated 16 characters in the 15th century.* There is also a story of William Shanks, who spent 20 years computing 700 Pi digits, but later it turned out that he was mistaken in the second part of the calculations.

Some modern men and women may think, as this relation is denoted by a Greek letter, so it was derived by a Greek mathematician. In fact, unfortunately, the history keeps silence about this. But there is evidence of who first used this designation in their work.

The proposition to designate the Pi number by the letter for the first time was introduced by the English mathematician, who was a teacher by profession. William Jones did it relatively long ago in 1706. **The book with this scientific work and investigation has a very compound name «Synopsis Palmariorum Matheseos».**

Later a little was established by the Swiss mathematician Leonard Euler, who used the well-known for every contemporary person designation for the first time. After his document was published this person received worldwide recognition. Soon after, there was a tendency to designate the number Pi with the help of the letter taken from Greek alphabet.

### Meaning

What does National Pi Day mean? Oh, all in all it is up to you to decide, whether this special occasion is important for you and the closest surrounding or it can be forgotten completely. The only thing we want to remind you is that the modern birthday of the Pi number was established on the initiative of American mathematicians. It is celebrated on March 14 at 1 and 59 minutes in the afternoon.

*This is due to the more accurate value of the Pi number: we are all used to thinking of this constant as 3.14, but the number can be continued as follows: 3, 14159 …* Translating this into a calendar date, we get 03.14, 1:59.

The day of the Pi is celebrated not as something original, but as an ordinary funny entertainment. Of course, scientists, who occupy exact sciences, do not miss it. For them it is a way not to break away from a loved one’s business, but at the same time to relax. On this day, people gather and cook different delicacies with the image of Pi. Especially there is where the pastry cook. They can make cakes with inscriptions in the form of a number «pi» and cookies of a similar shape. Having tasted delicacies, mathematicians arrange different quizzes.

## Definition

Discovering all the information possible as to the subject “When is International Pi Day 2018?” we should tell our readers that mathematicians all around the world do not stop conducting research related to the Pi number.

It is literally turned in a mystery. Some theorists even believe that it contains universal truth. To exchange knowledge and new information about Pi, it was organized the specialized Pi-club. To enter into it is not easy, as you need to have an extraordinary memory. *So, those wishing to become members of the club will be examined: a person must tell from memory as many signs of Pi as possible.*

Even a variety of techniques for remembering the number Pi after the decimal point have been already invented. For example, they come up with whole texts. In them, words have the same number of letters as the corresponding figure after the decimal point. To further simplify the memorization of such a long number, the specialists compose verses on the same principle.

Members of the Pi-club often have fun in this way, but at the same time they train memory and ingenuity. For example, Mike Keith had such a hobby, which eighteen years ago came up with a story, every word in which was almost four thousand (3834) of the first signs of the Pi number.

There is a curious coincidence. On March 14 the great scientist Albert Einstein was born, who, as we know, created the theory of relativity. Be that as it may, physicists can also join the celebration of the Day of Pi.

### Traditions

When is Pi Day in 2018, calendar will certainly remind you. **And in fact it is not difficult to memorize the date for ever. 3 is month, 14 – for day.** It is quite easy, isn’t it? But do you know how to celebrate March 14 in a proper way?

We advise you to organize a small party, to invite your friends and to try to remember as many constituents of this number as it is possible for you.

Pi is a well-known in some spheres mathematical constant, which shows and expresses the circumference ratio length to its diameter length. 3.14 is this numerical value that we substitute into formulas, solving problems in geometry.

In fact, the numbers after the decimal are much larger. To date, specialists know several trillions, calculated with the help of a computer. People are constantly competing in their memorization. Of course, to reproduce from memory all known figures of the Pi number are beyond the power of any person, but, nevertheless, there are record holders who could remember several thousand characters.

Hidiaki Tomoyori from Japan reproduced about 40,000 digits of the Pi number. To memorize it took him almost 10 years. In Russia, Alexander Belyaev managed to memorize 2500 signs. This is much less, but he spent only 1.5 months. All in all it is unknown what methods people used in order to succeed in remembering Pi number.

**Who will be the winner of your personal home contest?**

## International Pi Day Facts

So you have already known that the answer to “What is the date of National Pi Day 2018?” It is quite easy, isn’t it? However, now we are going to tell you something interesting about this special occasion celebrated in the beginning of the spring.

In different epochs and among different people, the Pi number had different meanings. For example, in Ancient Egypt it was 3.1604, for Indians it acquired the value 3.162, the Chinese used a number equal to 3.1459. Over time, π was calculated more accurately, and when computer technology appeared, the devices began to find out total more than 4 billion signs.

*It is noteworthy that the value of the Pi was attempted to be introduced even at the state level, that is, through the law.* In 1897, a bill was prepared in Indiana. According to the document, Pi was 3.2. However, scientists intervened in time and thus prevented the error. In particular, Professor Purdue, who was present at the legislative assembly, spoke against the bill.

Interestingly, their name has several numbers in an infinite sequence of Pi. So, six nines of the Pi number is named after an American physicist. Once Richard Feynman lectured and dumbfounded the audience with a remark. He said that he would like to learn by heart the numbers of Pi to six nines only in order to say six times «nine» at the end of the story, hinting that his meaning is rational. Whereas in fact it is irrational.