- In the Roman numeral system, the basic "digits" are the letters
**I**,**V**,**X**,**L**,**C**,**D**, and**M**which represent the same numbers regardless of their position. - Symbols are placed in order of value, starting with the largest values.
- When the higher numeral is placed before a lower numeral, the values of each Roman numeral are added.
- When smaller values precede larger values, the smaller values are subtracted from the larger values, and the result is added to the total.
- Do not repeat
**I**,**X**, and**C**more than three times in a row. (Number 4 on a Roman numeral clock is usually written as**IIII**. ) - Symbols
**V**,**L**, and**D**cannot appear more than once consecutively. - Do not subtract a number from one that is more than 10 times greater:
**I**may only precede**V**and**X**,**X**may only precede**L**and**C**, and**C**may only precede**D**and**M**.

I | 1 | XI | 11 |

II | 2 | XII | 12 |

III | 3 | XIII | 13 |

IV | 4 | XIV | 14 |

V | 5 | XV | 15 |

VI | 6 | XVI | 16 |

VII | 7 | XVII | 17 |

VIII | 8 | XVIII | 18 |

IX | 9 | XIX | 19 |

X | 10 | XX | 20 |

XXX | 30 | CL | 150 |

XL | 40 | CLIX | 159 |

XLIX | 49 | CXC | 190 |

L | 50 | CC | 200 |

LX | 60 | CCC | 300 |

LXX | 70 | CD | 400 |

LXXX | 80 | D | 500 |

XC | 90 | DC | 600 |

XCIX | 99 | CM | 900 |

C | 100 | M | 1000 |

When they needed to work with large numbers (4000 and above), the Romans often wrote a bar above a numeral, or parentheses placed around it, to indicate multiplication by 1000.

MMM | 3 000 000 | XLILXII | 41 062 |

XMXVII | 19 007 | XMCXI | 11 111 |

According to the old IUPAC recommendation before 1985, Roman numerals were used to denote the group in the periodic table of the elements. When the metal has more than one possible ionic charge or oxidation state the oxidation number (the same as the charge) of the metal ion is represented by a Roman numeral in parentheses immediately following the metal ion name. For example, FeO is iron(II) oxide and Fe_{2}O_{3} is iron(III) oxide.

- Calculator
- Scientific calculator for chemists
- Preparation of solutions
- Angle converter
- Roman numerals converter
- Number systems converter
- Oxidation numbers calculator
- Writing chemical equations on the Web

- Calculator for Chemists
- is a small but powerful scientific expression calculator which supports many scientific functions (sin, cos, log, power, root, memory, ...), normal and inverse. All of the calculations can be printed or saved and recalled again.
- Solution Calculator
- is a useful tool which allows you to calculate how many solid chemicals or stock solutions you will need to prepare the desired solution. The program provides lab-ready directions on how to prepare the desired solution.
- Unit & Number Converter
- helps you convert measurements from one unit of measurement to another (you can create your own custom units). It also includes the ability to convert the number from one numeral system into another (e.g. from binary into hexadecimal or Roman numeral system).

Citing this page:

Generalic, Eni. "Converting Roman Numerals To Arabic Numbers." *EniG. Periodic Table of the Elements*. KTF-Split, 9 July 2015. Web. {Date of access}. <http://www.periodni.com/roman_numerals_converter.html>.

Periodic table

Chemistry dictionary

Chemistry

Copyright © 2015 by Eni Generalic. All rights reserved. | Bibliography | Disclaimer