[nailer]

Two:

* Golden ratio is also miles to ks. Which means you can use Fibonacci to convert miles to ks.

* Divide by square route of two for compound doubling time.

[zalew]

kilometer is km not ks. just sayin'

[nailer]

One is an abbreviation. The other is a coloquial term, pronounced 'kays' used in most western speaking metric countries.