When did Arabic numerals replace roman numerals?

Answer 1

Roman numerals were common up until the 14th century. However, the Hindu-Arabic system, which replaced it, was first introduced in the 10th century, and was derived from the Indian numeral system first used in the 5th century. The Roman system started in around 400 BC but the system we use today didn't arrive until the 1st century AD (albeit without subtractive notation such as IV). There have been other numeral systems, including positional notation systems, that pre-date the Romans, as far back as 1,500 BC.