The Roman numeral system is internationally known and is based on seven letters that refer to the different numbers. Currently they are not used frequently and are only used to write dates and on some classic watch faces. They can also be found in inscriptions on certain monuments, to indicate a new chapter in a book or in relation to official events (for example, the reference to an edition of the Olympic Games).
The Roman numeral system
Each of the seven letters has a numerical value. Thus, the letter l is equal to 1, the letter V is equal to 5, the letter X is equal to 10, etc. Below is a table in which you can see all the equivalences.
Rules for writing Roman numerals
The rules for using this numbering are as follows:
1) According to the addition rule, a letter written to the right of another of equal or greater value, its value is added to this (for example, Xl is equal to 10 + 1 = 11 and CXV is equal to 100 + 10 + 5 = 115),
2) in the subtraction rule, the letters l, X and C to the left of another with a higher value subtracts its value from it (for example, lX is the same as 10 - 1 = 9, XC is the same as 100 -10 = 90 and CD equals 500-100 = 400),
3) in the repetition rule the letters l, X, C and M can be written in a row a maximum of three times (for example, CCC is equal to 100 + 100 + 100 = 300), and
4) In the multiplication rule, a line above a letter or group of letters multiplies its value by 1000.
The origin of Roman numerals
Humans begin to count as a necessity, especially in commercial activity and numbers are used when they realize that fingers or stones are not very useful for calculating. The first written records of Roman numerals date back to the 11th century AD. C and it is believed that the Romans were not the real inventors but it is very possible that they were the Etruscans, a people that inhabited the north of present-day Italy and that ended up being subdued by the Romans.
Other numbering systems
The numbering systems are very diverse and from a historical point of view we can highlight the Egyptian numbering, the Indo-Arabic system, the Mayan numbering or the current binary system.
In any case, the numbers are an abstraction of the mind that allow you to have control over reality.
Photos: iStock - Robert Zelichowski / susandaniels
