I guess it's similar to how we in the metric world would say "2000 kilometres" and not "2 megametres" (certainly not in an everyday context). > "a billion doll

I guess it's similar to how we in the metric world would say "2000 kilometres" and not "2 megametres" (certainly not in an everyday context). > "a billion dollars" This is only tangentially related to your point, but the word "billion" often gets mistranslated due to its two distinct meanings (long vs short scale). This could be another reason to avoid it. https://en.wikipedia.org/wiki/Billion https://en.wikipedia.org/wiki/Billion