hi! it's worth pointing out that not everyone does use 0-9 (known as Hindu-Arabic, or just Arabic, Numerals): some quick examples include Chinese and Thai. [edit: oh, found this handy table in wiki of various numeral systems.] As for the spread of Arabic Numerals, a great place to start is /u/Jooseman's overview here:

• When and how did Arabic numbers get adopted worldwide?

and here are some earlier posts that may be of interest

• When and how did Asian countries switch to the use of Arabic numerals?

• How and when did the arabic numbers took over the roman numbering system in Europe?

• Why did Arabian numerals become the dominant numerals in Europe over Roman numerals?

• Why were Arabic numerals so effective when 11th century Europe started to use them?

• When did Roman numerals stop being used?

• At what point did it seem Western culture switched from "Roman" numerals (I,V,X,etc.) to the more modern, "Arabic-Hindu" numerals (1,2,3,etc.)?

• How did the Arabic numerals become the world standard, essentially, for enumeration?

• What kind of counting systems did they use in Europe before Arabic numerals became widespread?