The Roman numbering used seven capital letters correspond to the following values:
To write all the numbers, you must meet the following rules:
1ª If the right of a Roman letter is written the same or lower, the value it adds to the previous one.Examples: VI = 6; XXI = 21; LXVII = 67
2ª The letter "I" placed before the "V" or "X", subtracts a unit to the next; the letter "X", preceding the "L" or "C", subtracts ten units to the next and the letter "C", preceding the "D" or "M", subtracts hundred units to the next.
3ª The same letter can not be repeated more than three times in any number.Examples: XIII = 13; XIV = 14; XXXIII = 33; XXXIV = 34
4ª The letters "V", "L" and "D" can not be duplicated because there are other "X", "C" and "M" representing its value doubled.
5ª If in the middle of two letters there is another of less value, it subtracted its value to the next.
6ª The value of Roman numerals is multiplied a thousand times as many horizontal lines are placed above them.
The games in the menu will help you learn how to write Roman numerals.