Trick to convert Miles to Kilometres and vice versa

The interesting thing about Miles are that they are approximately 1.6 times a Kilometre. So, what? Well as it turns out 1.6 is known as the golden ratio or the ratio between two consecutive fibonacci numbers. Fibonacci numbers are in the following sequence

0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55 etc..

That is

1 + 0 = 1
1 + 1 = 2
2 + 1 = 3
3 + 2 = 5
5 + 3 = 8
8 + 5 = 13

Now, dividing the two consecutive fibonacci numbers gives you approximately 1.6. ie.  13/8 is 1.625.

So, now if you take 3 consecutive fibonacci numbers, then the lower one will be the distance in miles and the upper one will be in kilometres.

That answers the question of how long is a 5K Run? Its the previous fibonacci number - 3 i.e 3 Miles (approximately. The real distance is 3.1 miles).

How long is 50 kms? Approximately 31-32 miles... (55 is 34 miles. Now subtract 5 kilometers i.e 3 miles).

How long is a marathon? 26 miles. That means its 21 + 5 miles therefore, 34 + 8 kms which is 42 kilometres. Neat huh!