I have it on consumer-grade authority that the Indians got them in turn from the Shang dynasty, decimal since ca.1200BCE. Thus proving conclusively that numeral systems naturally travel deasil. Ne'er let thine diʒits, goe widdershins.

Also as long as we are going down the terminology nerd rabbit hole: it's Arabic numerals, not numbers. Numbers refers to the abstract concept, numerals refers to the method one uses to write them down.

If you want to go down the terminology nerd rabbit hole, which I think is the correct thing to do, it's not even called Arabic language, it's called The Un-ambiguous Arabic Tongue (my translation of اللسان العربي المبين). Language (which comes from the word لغة) is a bad word, it means "idle chatter". Tongue is the correct term for someone who knows what they're talking about. Modern Arabic (even what is referred to as Classical Arabic) is a deviation from The Un-ambiguous Arabic Tongue. A lot of ignorant people think that the Quran is poetry when in fact it is in The Un-ambiguous Arabic Tongue, which again many people don't know (or intentionally hide!). The Arabs who spoke that tongue eloquently back then denounced poetry and poets (that's why when they wanted to curse at the prophets they called the prophets "crazy poets". Read the Quran for reference) To them poets are crazy, and the Quran was chosen by Allah to come down in that specific tongue, hence the Quran also denounces poetry.

Yeah - I quoted that to show that it was normal usage rather than technical correctness - I also did the same for the name that I didn't have the correct spelling for as I wrote the comment - not sure if I should update it (with your input) or to leave it and let people work down the thread

it's a cardinal rule