...for calculating the famous Golden Ratio, that is. But hang on, you remember the Fibonacci numbers, right? Start with 1, then add the previous number to get the next one, like so:
1, 1, 2, 3, 5, 8, 13...
The ratio between each successive pair of numbers will approach the Golden Ratio (roughly 1.61803). The problem is that it takes a long time to for the Fibonacci numbers to get to a good approximation. And what's more, it turns out you can get a similar approximation by taking any two numbers and iterating them in the Fibonacci style. Pick some big ones, and the series will approach faster.
And I mean literally any numbers picked out of a hat. Fascinating! --Ryan Cooper