Feb 9, 2024
Fun little math trick I find really helpful: the ratio of a mile to a kilometer is within 1% of the Golden Ratio. That means that if you have a good memory for Fibonacci numbers (1 2 3 5 8 13 21 34 55 89) you can convert pretty accurately by taking consecutive Fibonacci numbers.
For example, 89 kilometers is really close to 55 miles (55.3). Or, say you need to convert 26 miles to kilometers: 26 can be written as 21 plus 5, so taking the next Fibonacci number up gives 34 and 8, meaning it should be around 42 kilometers. Sure enough, it's 41.8 km!
