Hotel Floor Numbering
The way we number floors in public buildings differs by country. Here's a picture showing four sixteen storey hotels:
The first difference occurs on the bottom floor. In England and most of Europe it is usual to start with the ground floor and then start numbering as you go up. It is like you are treating G as zero which is useful if you have multiple basements which can be numbered -1, -2 etc. The rest of the world doesn't do this and instead prefer the number of the floor to match which storey (story in American) it is on.
Next we have the unlucky 13 thing that many western countries or recently ex colonies often do.
While China doesn't do this, they do take out all numbers with a four in them. The word sounds like the word for death and it is considered deeply unlucky. Many skyscrapers will miss out everything from 39 to 50 aswell.
Hong Kong manages to be a mix of all of these conventions: a merger of British and Chinese customs.
All in all it is a bit of a mess.