# Roman Numerals

The numbers that we normally use (1, 2, 3 etc) are called "Arabic numerals". But we sometimes use another system for writing numbers - "**Roman numerals**". The Romans used **letters of the alphabet** to represent numbers, and you will occasionally see this system used for page numbers, clock faces, dates of movies etc.

The letters used in Roman numerals are:

- I = 1
- V = 5
- X = 10
- L = 50
- C = 100
- D = 500
- M = 1000

We can use upper-case letters (capitals) or lower-case letters (small letters) when writing Roman numerals. So the following numbers are exactly the same:

**XVIII**=**xviii**=**18**In general, letters are placed in decreasing order of value, e.g. XVI = 16 (10+5+1). Letters can be repeated one or two times to increase value, e.g. XX = 20, XXX = 30. Letters cannot be repeated three times, so XXXX is not used for 40. In this case, XL = 40 (50 minus 10).

Do not be fooled by the word

*repeat*, which means "do again". If we write X and then repeat it, we have XX. If we repeat X two times, we have XXX. So XXX is X repeated two times, not three times!Look at these examples of Roman numerals in use:

**The Introduction is on page vii**(= The Introduction is on page 7)**© MMXVI EnglishClub**(= © 2016 EnglishClub)

## Significant numbers from one to a thousand

Roman numerals | Arabic numerals | |
---|---|---|

upper-case | lower-case | |

I | i | 1 |

II | ii | 2 |

III | iii | 3 |

IV | iv | 4 |

V | v | 5 |

VI | vi | 6 |

VII | vii | 7 |

VIII | viii | 8 |

IX | ix | 9 |

X | x | 10 |

XI | xi | 11 |

XII | xii | 12 |

XIII | xiii | 13 |

XIV | xiv | 14 |

XV | xv | 15 |

XVI | xvi | 16 |

XVII | xvii | 17 |

XVIII | xviii | 18 |

XIX | xix | 19 |

XX | xx | 20 |

XXI | xxi | 21 |

XXII | xxii | 22 |

XXIII | xxiii | 23 |

XXX | xxx | 30 |

XL | xl | 40 |

L | l | 50 |

LX | lx | 60 |

LXX | lxx | 70 |

LXXX | lxxx | 80 |

XC | xc | 90 |

C | c | 100 |

CC | cc | 200 |

CCC | ccc | 300 |

CD | cd | 400 |

D | d | 500 |

M | m | 1000 |