Apart from telling sick jokes, Roman numerals really don't have much going for them. Adding CLXXVII to XXIII may be relatively straightforward, but try multiplying CLXXVII by XXIII or dividing CLXXVII by XXIII.
These days you see Roman numerals only in descriptions and references, such as sequels to films (e.g. Rocky III), dates on statues and public buildings, names of monarchs and popes (e.g. Elizabeth II), and also on coinage, general suffixes, sporting events (e.g. Superbowl XLIX), and copyright dates on movie credits and TV shows. And the odd sick joke!
So that you can work out for yourself the copyright date of that old movie you thought was rather corny, here are the very simple rules: (which I was taught before I left German primary school in MCMLX)
There are just seven Roman numerals:
I (1), V (5), X (10), L (50), C (100), D (500), and M (1000).
And there are just three simple rules:
- If a smaller numeral comes after a larger numeral, add the smaller number to the larger number
- If a smaller numeral comes before a larger numeral, subtract the smaller number from the larger number
- Do not use the same symbol more than three times in a row
The rule of not using the same symbol more than three times in a row means that the highest number in pure Roman numeral form is 3,999 - which is written as MMMCMXCIX - because the number 4,000 would have to be written as MMMM which would make for an even sicker joke.
Want to talk about Roman numerals? Call me on XLIV LXXVIII X LXXXI.
P.S. Roman sleeping habits aside, how did the Romans pronounce their numbers? In base-10, but with some quirks, but far fewer quirks than modern French counting. With a few oddities like one and three declining to the nouns gender (unus/tres for masculine, una/tria feminine), the numbers progressed as a usual base-10 system goes until 18, 28, 38, etc all of which were the next 10-number minus two.
So 18 was duodēvīgintī ‘two from twenty’ and 19 was ūndēvīgintī ‘one from twenty.’ 28 was duodētrīgintā ‘two from thirty’ and so on. The numbers 1–17, and 20–27, etc progressed as a normal base-10 counting system does. I thought you'd be interested to know.
As for French, don't even get me started but here it is: French is base-20 instead of base 10 from the number 60–99. 70 is Soixante dix literally ‘sixty ten’ and 71 is Soixante et onze ‘sixty and eleven’ until 80, which is Quatre-vingts ‘four twenties’ and then that goes all the way to 99 which is Quatre-vingt dix-neuf ‘four twenty nineteen.’
