The reason why I ask this question is because of the pattern I've seen with Japanese numbers. Once you have to repeat a number to describe itself, you get a new unit. For example, 十十 = 百, 百百 = 万, 万万 = ...
While visiting Tokyo, I noticed that most levels were indicated by B2F, B1F, 1F, 2F, ... . This doesn't look like the Romaji for -kai or -gai counter-words, which I assume would be chika ni-kai, ...