Our number system emigrated form India over Arabia to Europe and then the Americas and Australia. Which leaves little left. So the question turns into: What happens east of India? E.g. China has its own numbers, and the Babylonians had 60 as a base. And what about the aborigines in Australia, tribes in the Amazon rainforest, or the first nations. My guess is, that it has basically been driven by trade. Talk whatever you like, but when it comes to money, ambiguities aren't fun anymore. However, it took the European traders embarrassingly long to change from the stupid Roman number system to the Arabian decimal system.