Archive

Topic: Numbers

Fact Twenty-three people give you a better than even chance of a shared birthday It feels like it should take hundreds. It takes a small classroom. 1 min read Fact Fold a piece of paper 42 times and it reaches the Moon In principle. In practice you will stop at about seven. 1 min read Fact Switching doors doubles your odds, and almost nobody believes it Professional mathematicians wrote in to say it was wrong. It was not. 1 min read Fact Real-world numbers start with 1 far more often than chance allows About 30 per cent of the time. Tax authorities use this to catch fraud. 1 min read Fact Some infinities are bigger than others There are more numbers between 0 and 1 than there are whole numbers, and it can be proved in a paragraph. 1 min read Fact NASA uses only fifteen decimal places of pi Enough to calculate a circle the size of the solar system to within a centimetre. 1 min read Fact Rice on a chessboard bankrupts a kingdom One grain on the first square, doubling each time. By square 64 you owe more rice than exists. 1 min read Fact Zero took centuries to be accepted in Europe Some Italian cities banned it as an invitation to fraud. 1 min read