Roman numerals are the standard way of numbering used by the romans in ancient Rome. In Arabic number system, we have digits from 0 - 9 and we can make as big a number as we want with these. Numbers from 1 - 9 are used to make various calculations which we use in our daily life. The Roman system is expressed by letters of the alphabet and symbols can be used to represent numbers. |

Number |
Roman Numerals |
Explanation |

1 | I | One |

2 | II | Two |

3 | III | Three |

4 | IV | Here we use a smaller numeral before a larger numeral means, subtract it from that numeral. |

5 | V | Five |

6 | VI | Six |

7 |
VII | Seven |

8 | VIII | Eight |

9 | IX | Nine - As there would be four fours in a row (VIIII), we use the shorthand of writing it in roman numerals. |

10 | X | Ten |

There are some rules to be followed for writing the Roman Numerals:

- Symbols that can be repeated three times are I, X, C and M. The rest symbols can be used more than once.
- Symbols that can be used for addition and subtraction are I, X and C. When we place a smaller symbol at the left of the bigger symbol, it indicates subtraction and if we place a smaller symbol on the right, it indicates addition.
- A symbol ‘I’ can be added to any roman symbol, but it can be subtracted from only two symbols namely ‘V’ and ‘X’.
- 'X’ can be added to all symbols, but can be subtracted from ‘L’ and ‘C’ only.
- ‘C’ can be added to every symbol, but can be subtracted from ‘D’ and ‘M’ only.
- A bar placed on top of a letter or string of letters increases the numeral's value by 1,000 times.

XV = 15, $\bar{X}$$\bar{V}$ = 15,000 - Remember the meanings of the letters,

M = 1000, D = 500, C = 100, L = 50, X = 10, V = 5, I = 1. - A smaller numeral to the left of a larger could mean multiplication.

Example: XM = 10000.

Number |
Roman Numeral |

0 | Not defined |

1 | I |

2 | II |

3 | III |

4 | IV |

5 | V |

6 | VI |

7 | VII |

8 | VIII |

9 | IX |

10 | X |

14 | XIV |

15 | XV |

19 | XIX |

20 | XX |

30 | XXX |

40 | XL |

50 | L |

60 | LX |

70 | LXX |

80 | LXXX |

90 | XC |

100 | C |

200 | CC |

300 | CCC |

400 | CD |

500 | D |

600 | DC |

700 | DCC |

800 | DCCC |

900 | CM |

1,000 | M |

5,000 | $\bar{V}$ |

10,000 | $\bar{X}$ |

50,000 | $\bar{L}$ |

1,00,000 | $\bar{C}$ |

5,00,000 | $\bar{D}$ |

1,000,000 | $\bar{M}$ |

### Solved Examples

**Question 1:**Convert 145 to Roman Numerals.

**Solution:**

Break 145 into 100, 40, and 5.

Do each conversion as

100 = C

40 = XL

5 = V

From above, 145 in roman numerals is written as

145 = CXLV

Do each conversion as

100 = C

40 = XL

5 = V

From above, 145 in roman numerals is written as

145 = CXLV

**Question 2:**Convert 1545 to Roman Numerals.

**Solution:**

Break 1545 into 1000, 500, 40 and 5.

Do each conversion as

1000 = M

500 = D

40 = XL

5 = V

From above, 1545 in roman numerals is written as

1545 = MDXLV

Do each conversion as

1000 = M

500 = D

40 = XL

5 = V

From above, 1545 in roman numerals is written as

1545 = MDXLV

**Question 3:**Convert 4936 to Roman Numerals.

**Solution:**

Break 4936 into 4000, 900, 30 and 6.

Do each conversion as

4000 = $\bar{IV}$

900 = CM

30 = XXX

6 = VI

From above, 4936 in roman numerals is written as

4936 = $\bar{IV}$CMXXXVI.

Do each conversion as

4000 = $\bar{IV}$

900 = CM

30 = XXX

6 = VI

From above, 4936 in roman numerals is written as

4936 = $\bar{IV}$CMXXXVI.