Dinner Table Math
Math Facts That'll Make You Say "Wait, What?" #13
Every triangle you have ever drawn adds up to 180 degrees, exactly, no exceptions. A stop sign has eight sides because someone chose that on purpose in 1923. And a square is, technically, a rectangle. Shapes are quietly doing more work than they let on.
Math Facts That'll Make You Say "Wait, What?" #12
A million seconds ago was eleven days ago. A billion seconds ago was 1992. Sonic was new, the web had just opened to the public, the first text message had not been sent yet. The words sound like the same category of big. The numbers are not even in the same country.
Math Facts That'll Make You Say "Wait, What?" #11
The digit 8 is three different numbers depending on how you slice it. The 9 times table doesn't just repeat. It builds perfect number pyramids. And spiders are doing geometry in the dark that humans needed centuries of maths to describe.
Math Facts That'll Make You Say "Wait, What?" #10
Counting to a million out loud, one number per second, would take 23 days without stopping. Counting to a billion would take 31 years. Two is the only even prime number in existence. Forty is the only number in English whose letters appear in alphabetical order.
Math Facts That'll Make You Say "Wait, What?" #9
Sunflower seeds arrange themselves in Fibonacci spirals without knowing what a Fibonacci number is. Multiply 21,978 by 4 and read the answer backwards. And 0.999... repeating is mathematically equal to 1. This last one has started more arguments than almost anything else in mathematics.
Math Facts That'll Make You Say "Wait, What?" #8
A pizza has height and thickness, which makes it a cylinder, not a circle. Every snowflake has exactly six sides, always, because of the shape of a water molecule. And 111,111,111 multiplied by itself produces a number that counts up to 9 and straight back down again.
Math Facts That'll Make You Say "Wait, What?" #7
Multiply 142857 by 2, 3, 4, 5, or 6 and it rearranges its own digits every time. Multiply it by 7 and it collapses into six nines. A properly shuffled deck of cards has almost certainly never been in that order before in history. The equals sign was invented by someone who was tired of writing.
Math Facts That'll Make You Say "Wait, What?" #6
Carl Friedrich Gauss was 8 years old when he added every number from 1 to 100 in his head in roughly thirty seconds. Nine, for its part, has been performing the same trick in every multiplication table since the beginning of arithmetic.
Math Facts That'll Make You Say "Wait, What?" #5
Multiply 11 by itself and you get a palindrome. Keep going with 111, 1111, 11111 and the palindromes build into perfect number pyramids. Bees, separately, solved the most efficient geometry problem in nature millions of years before any mathematician could prove they'd done it.
Math Facts That'll Make You Say "Wait, What?" #4
The Romans had no symbol for zero. This wasn't a minor gap, it made their entire number system nearly unusable for anything complicated. Four, meanwhile, is the only number in English whose name contains exactly as many letters as its value.
Math Facts That'll Make You Say "Wait, What?" #3
Some infinities are larger than others. Georg Cantor proved this in the 1870s and it made several of his colleagues extremely angry. Also: you cannot fold a piece of paper in half more than seven or eight times, and if you could fold it 42 times it would reach the Moon.
Math Facts That'll Make You Say "Wait, What?" #2
Spell out any odd number in English and the letter "e" is in there. Every single one, all the way to infinity. Then there's the 'googol'. It is bigger than all the atoms in the observable universe, named by a 9-year-old who was asked to think of something enormous.
Math Facts That'll Make You Say "Wait, What?" #1
The Koch Snowflake has an infinite perimeter that fits inside a finite space. Pi has been calculated to 105 trillion decimal places and nobody knows if it ends. Two facts that have nothing to do with homework and everything to do with why maths is strange.