Ian was waiting impatiently for Rhiannon to get off the computer so he could have a turn. I pointed to the clock in that room, which happens to have Roman Numerals, and told him how much time he had left to wait. Then I asked him if he’d like me to show him how to read Roman Numerals.
I wrote Arabic and Roman symbols in two columns like this, and showed him how we subtract if the smaller numeral is in front or add the smaller numeral if it follows the larger.
After figuring out a few examples together, I wanted to show him the larger numerals but I wasn’t sure whether M was 1000 or a million, so I googled. We found this comic book all about Roman Numerals. Ian, who read about half of the book, was most amused by this page, which suggests a mnemonic for remembering the numerals.
Another page of the book has a Roman Numeral Converter so you can check your calculations. I just discovered that my kids’ birth years are so much easier to write in Roman Numerals than my own! Mine is MCMLXXI but my kids’ are MMI, MMIII, and MMVI respectively.
Ian said Roman Numerals are “pretty hard to understand at first,” but we had some math exercise and an interesting little trip through history.