I |
The easiest way to note down a number is to make that many marks -
little I's. Thus I means 1, II means 2, III means 3. However, four
strokes seemed like too many.... |

V |
So the Romans moved on to the symbol for 5 - V. Placing I in front
of the V — or placing any smaller number in front of any larger number —
indicates subtraction. So IV means 4. After V comes a series of
additions - VI means 6, VII means 7, VIII means 8. |

X |
X means 10. But wait — what about 9? Same deal. IX means to subtract
I from X, leaving 9. Numbers in the teens, twenties and thirties follow
the same form as the first set, only with X's indicating the number of
tens. So XXXI is 31, and XXIV is 24. |

L |
L means 50. Based on what you've learned, I bet you can figure out
what 40 is. If you guessed XL, you're right = 10 subtracted from 50. And
thus 60, 70, and 80 are LX, LXX and LXXX. |

C |
C stands for *centum*, the Latin word for 100. A *centurion*
led 100 men. We still use this in words like "century" and "cent." The
subtraction rule means 90 is written as XC. Like the X's and L's, the
C's are tacked on to the beginning of numbers to indicate how many
hundreds there are: CCCLXIX is 369. |

D |
D stands for 500. As you can probably guess by this time, CD means
400. So CDXLVIII is 448. (See why we switched systems?) |

M |
M is 1,000. You see a lot of Ms because Roman numerals are used a
lot to indicate dates. For instance, this page was written in the year
of Nova Roma's founding, 1998 CE (Common Era; Christians use AD for Anno
Domini, "year of our Lord"). That year is written as MCMXCVIII. But
wait! Nova Roma counts years from the founding of Rome, *ab urbe
condita*. By that reckoning Nova Roma was founded in 2751 a.u.c. or
MMDCCLI. |