# Roman Numerals

Ancient Romans used a special method of showing numbers

Examples: They wrote **C** instead of **100**

And wrote **IX** instead of **9**

*Read on to learn about Roman Numerals or go straight to the Roman Numeral Conversion Tool*.

## The Roman Symbols

Romans Numerals are based on the following symbols:

1 | 5 | 10 | 50 | 100 | 500 | 1000 |
---|---|---|---|---|---|---|

I |
V |
X |
L |
C |
D |
M |

## Basic Combinations

Which can be combined like this:

1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |
---|---|---|---|---|---|---|---|---|

I |
II |
III |
IV |
V |
VI |
VII |
VIII |
IX |

10 | 20 | 30 | 40 | 50 | 60 | 70 | 80 | 90 |
---|---|---|---|---|---|---|---|---|

X |
XX |
XXX |
XL |
L |
LX |
LXX |
LXXX |
XC |

100 | 200 | 300 | 400 | 500 | 600 | 700 | 800 | 900 |
---|---|---|---|---|---|---|---|---|

C |
CC |
CCC |
CD |
D |
DC |
DCC |
DCCC |
CM |

## Forming Numbers - The Rules

When a symbol appears **after a larger** (or equal) symbol it is **added**

- Example: VI = V + I = 5 + 1 = 6
- Example: LXX = L + X + X = 50 + 10 + 10 = 70

But if the symbol appears **before a larger** symbol it is **subtracted**

- Example: IV = V − I = 5 − 1 = 4
- Example: IX = X − I = 10 − 1 = 9

To Remember: **A**fter Larger is **A**dded

Don't use the same symbol more than three times in a row (but IIII is sometimes used for 4, particularly on clocks)

## How to Convert to Roman Numerals

Break the number into Thousands, Hundreds, Tens and Ones, and write down each in turn.

### Example: Convert 1984 to Roman Numerals.

Break 1984 into 1000,900, 80 and 4, then do each conversion

- 1000 = M
- 900 = CM
- 80 = LXXX
- 4 = IV

1000 + 900 + 80 + 4 = 1984, so **1984 = MCMLXXXIV**

## How To Remember

Think "MeDiCaL XaVIer".

It has the roman numerals in descending order from 1000 to 1.

I, for one, like Roman numerals!

## Really Big Numbers

Numbers greater than 1,000 are formed by placing a dash over the symbol, meaning "times 1,000", but these are not commonly used:

5,000 |
10,000 |
50,000 |
100,000 |
500,000 |
1,000,000 |
---|---|---|---|---|---|

V |
X |
L |
C |
D |
M |

## Conversion Tool

You can convert to/from Roman Numerals here: