250 Fun Facts
250 Amazing Facts: Dinosaurs, Maths, Money, Travel & the Mind
Numbers & Maths Facts
The equals sign (=) was invented in 1557 by Welsh mathematician Robert Recorde, who used two parallel lines because "no two things can be more equal."
The plus and minus signs first appeared in a printed book in 1489.
Using powerful computers, pi has been calculated to more than 100 trillion digits, and it never ends or repeats.
Pi Day is celebrated on 14 March (3/14), which also happens to be Albert Einstein's birthday.
A "googol" is the number 1 followed by 100 zeros. The name Google was inspired by it.
Zero is an even number.
111,111,111 multiplied by 111,111,111 equals 12,345,678,987,654,321.
Every odd number written in English contains the letter "e."
"Forty" is the only number in English whose letters are in alphabetical order.
Srinivasa Ramanujan saw magic in numbers
Self-taught Indian mathematician Srinivasa Ramanujan made extraordinary discoveries in number theory. When his friend G. H. Hardy mentioned that his taxi number, 1729, seemed dull, Ramanujan instantly replied that it was the smallest number that can be written as the sum of two cubes in two different ways. India celebrates National Mathematics Day on 22 December, his birthday.
Around 499 CE, Indian mathematician Aryabhata calculated pi as approximately 3.1416, remarkably close to the true value.
The Fibonacci sequence, where each number is the sum of the two before it, appears in nature, from the spirals of sunflower seeds to pinecones.
Indian scholars described the sequence now called the Fibonacci sequence centuries before Fibonacci introduced it to Europe.
Roman numerals have no symbol for zero.
The infinity symbol (∞) was introduced by English mathematician John Wallis in 1655.
The word "algorithm" comes from the name of 9th-century Persian mathematician al-Khwarizmi, and "algebra" comes from the title of his book.
In China and Japan, the number 4 is often considered unlucky because it sounds similar to the word for "death."
Many tall buildings skip the 13th floor because of superstitions about the number 13.
In a group of just 23 people, there's a better than 50% chance that two of them share the same birthday.
Shakuntala Devi was known as the "Human Computer"
Indian mathematician Shakuntala Devi could perform huge calculations in her head faster than many machines. In 1980, she correctly multiplied two 13-digit numbers in just 28 seconds, a feat recorded by Guinness World Records. She toured the world showing that maths could be exciting and fun.
On a standard die, the numbers on opposite faces always add up to 7.
A pizza with radius "z" and thickness "a" has a volume of pi × z × z × a, which spells "pizza."
If you take almost any four-digit number with at least two different digits, arrange its digits from largest to smallest and smallest to largest, and subtract, repeating the process will always lead to 6174. It's called Kaprekar's constant, after Indian mathematician D. R. Kaprekar.
The more closely you measure a coastline, the longer it gets, because you include more and more tiny bends. This puzzle is called the coastline paradox.
Two is the only even prime number.
A Möbius strip, made by giving a strip of paper a half-twist and joining the ends, has only one side.
A circle has an infinite number of lines of symmetry.
We have 60 minutes in an hour and 360 degrees in a circle because of the ancient Babylonians, who counted in base 60.
Ancient Egyptians wrote most fractions with 1 as the top number, such as 1/2, 1/3 and 1/4.
Fermat's Last Theorem took 358 years to prove
In 1637, French mathematician Pierre de Fermat scribbled in the margin of a book that he had a proof for a famous number puzzle but that the margin was too small to contain it. Mathematicians tried for centuries to find the proof, until British mathematician Andrew Wiles finally cracked it in 1994.
The golden ratio, about 1.618, has fascinated artists, architects and mathematicians for centuries.
Bees build hexagonal honeycomb cells because hexagons hold the most honey while using the least wax.
The word "mathematics" comes from the Greek word "mathema," meaning "learning."
Euclid's "Elements," a maths book written more than 2,000 years ago, is one of the most widely published books in history.
Hypatia of Alexandria, who lived around 1,600 years ago, is one of the first known female mathematicians.
French mathematician Sophie Germain used a male pen name so that her work would be taken seriously in the early 1800s.
Before astronaut John Glenn's orbital flight in 1962, he asked NASA mathematician Katherine Johnson to personally check the computer's calculations.
If you add up the digits of any multiple of 9, the result is always a multiple of 9.
A "googolplex" is 1 followed by a googol of zeros. There isn't enough space in the known universe to write it out in full.
Euler's identity is often called the most beautiful equation
Swiss mathematician Leonhard Euler's identity, e^(iπ) + 1 = 0, links five of the most important numbers in mathematics: e, i, π, 1 and 0. Many mathematicians consider it the most elegant equation ever written, because it connects so many different areas of maths in one short line.
Some infinities are bigger than others. German mathematician Georg Cantor proved there are more real numbers than whole numbers, even though both go on forever.
In the famous Monty Hall puzzle, switching your choice of door doubles your chance of winning the prize, even though it feels like it shouldn't matter.
"Lilavati," a 12th-century maths book by Indian mathematician Bhaskara II, presents problems as charming word puzzles.
More than 2,000 years ago, Indian scholar Pingala described a system for poetic rhythms that worked much like modern binary numbers.
A "baker's dozen" means 13, not 12.
Sudoku became popular in Japan, but the puzzle was first published in the United States in 1979 under the name "Number Place."
A game of tic-tac-toe will always end in a draw if both players make the best possible moves.
The digits 0 to 9 that we use every day are called Hindu-Arabic numerals, because they began in India and spread to Europe through the Arab world.
The multiplication sign (×) was introduced by English mathematician William Oughtred in 1631.
Manjul Bhargava won maths' highest honour
In 2014, Canadian-American mathematician Manjul Bhargava, whose family is from India, won the Fields Medal, often called the Nobel Prize of mathematics. Some of his work was inspired by ancient Sanskrit texts and the ideas of the Indian mathematician Brahmagupta, and he is also a skilled tabla player.
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