Fibonacci numbers can be used to convert between miles and kilometers with surprising accuracy. By taking two consecutive Fibonacci numbers, the ratio between them is close to the Golden ratio, which is approximately the same as kilometers per mile. For example, 5 miles is approximately 8 kilometers, and 21 miles is approximately 34 kilometers. If the distance is not a Fibonacci number, it can be expressed as a sum of Fibonacci numbers for conversion. This method is within 1% of the precise answer and is a clever mathematical trick based on the properties of Fibonacci numbers and the Golden ratio. It’s a unique way to do conversions that many may not have heard of before.
https://catonmat.net/fibonacci-miles-kilometers