The PD. is a strange celebration of the mathematical constant that is found dividing the circumference of the circle with its diameter, which is 3.14 when it is rounded to two decimal places. If you have friends or colleagues who want to showcase their dominance in the fifth geometry and economy of the sixth grade, you can even get a pot from home. But what about those of us with an appetite for math holidays who find the stables' ceremonies to be pretty much predictable?

## Fibonacci Day (November 23)

Each number in the Fibonacci sequence is the sum of the two numbers before that. If you add 1 and 1, will you get 2? if you then add 1 and 2, you get 3, so 23 November is the most appropriate day to celebrate the participation of Italian mathematician Fibonacci in his title. How do you mark the opportunity? We suggest a Fibonacci potluck: Each contribution to the meal should be quantified by the sum of the two contributions before that.

Say Adam brings a salami and Sally brings a wooden board. This is a party festive sausage cake! But if Molly brings two bottles of wine, Jasper brings three pieces of cheese and Dakota brings five rolls of dinner, now you have a little bit of Fibonacci antipasto.

## Hilbert Day (February 3rd)

The German mathematician David Hilbert had a set of complicated problems-23, to be exact, hence the date – and wanted someone else to solve them. Can not you relate? Give people a break! Hilbert's problems helped shape the direction of the mathematical study throughout the 20th century, although there are different claims about which they have been finally resolved. However, several theorems developed over the past century and address problems such as Matiyasevich's theorem, which combines theory of computational theory and numerical theory and the Gelfond-Schneider theorem, which determined that any algebraic number other than 0 or 1 square the irrational number is a transcendent number.

Hilbert's Day must inspire us to seek answers, but to embrace the unknown and ambiguity. To celebrate Hilbert, celebrations should eat a ripe tomato in recognition of the double identity of the plant as a fruit (according to the botanists) and a vegetable (according to all others). Being in this limiting space reflects the pleasure and pain of doing mathematical evidence.

## Pythagorean Day (16 December 2020)

You will have more than enough time to prepare for these last holidays when the sum of the month and day squared equals the last two digits of the year square. Any math fan probably had a difficult time, knowing the lengths of both sides of a right triangle, but not the third. Fortunately, the Greek mathematician Pythagoras has covered us since 500 BC. with its theorem: you can calculate the length of a right triangle subtitle by finding the square root of the sum of the square values of its two other lengths.

To celebrate the Pythagorean day, it's all triangles: cut the sandwich diagonally, eat a slice of pizza or pull the gang on the samos – just stay away from the circles at all costs!