The basics: When a smaller number is in front of a larger one, it is subtracted from the larger number. When the smaller number is in front of the larger number, it is added.
Example: 9 = IX, 400 = CD, 2022 = MMXXII
There are some additional rules. For example, 99 is not usually represented as IC, but rather XCIX (90 + 9)
I don't think I need to explain how to use these.
So the question is, why are they called Hindu-Arabic numerals?
Western nations call them Arabic because Europe got the numerals from the Islamic world, which got them from the Hindus. To acknowledge both cultures, it’s best to refer to them as Hindu-Arabic.
Did you know that the Hindus also invented 0?
Share these cool facts with friends and family. I bet they’ll be surprised.