Roman Numerals History and Facts

In the modern world, their usage has been mostly confined to clocks, watches, specific texts or sporting events. However, Roman numerals were the numbering system that was used for hundreds of years throughout the Roman Empire and during the Middle Ages. They were used not only for complicated mathematical purposes but also in everyday life. So what are the origins of Roman numerals? When were they created? Where do the Roman numeral symbols come from?

What Are Roman Numerals?

Roman numerals are a numeric system that was used in the Roman Empire. They were used in Europe for nearly 2000 years. The seven symbols that represent the Roman numbers are letters from the Latin Alphabet. The letters I, V, X, L, C, D and M are used with assigned values in order to write numbers.

The letters and their values in Roman numeral system are as follows:

I V X L C D M

1 5 10 50 100 500 1,000

In the Roman Empire, these numbers were widely used in everyday trade and services as well as in complicated mathematical applications such as accounting, architecture and engineering.

After the fall of the Roman Empire, their use continued in Europe until the 15th century. However, it was realised in time that the Arabic numbers (the numeral system we use today) was easier in everyday life and in calculations that deal with larger numbers.

Also, the fact that the number 0 was not represented in the Roman system was a problem. Therefore, Roman numerals were gradually replaced by the more convenient Arabic numeral system. Meanwhile, their use in religious texts and many other areas continued.

Origins of Roman Numerals

The Roman numerals are based on the Etruscan numbering system, the civilisation that the Roman Empire was built upon. There are two competing theories as to where the letters come from:

Tally Stick Theory

This theory suggests that the origins of Roman numerals lie in a tally system used by shepherds to count their sheep. According to this theory, shepherds in Rome used to keep their sheep tally by using sticks. Each animal was recorded on a stick with a notch carved with a knife. The fifth sheep would have two notches in the shape of a ‘V’ and the tenth was an ‘X’.

This would mean that, for example, eight sheep would have a ‘notch series’ of IIIIVIII. When shortened, there were VIII sheep, identical to the Roman numerals. Sixteen sheep on a tally stick would look like IIIIVIIIIXIIIIVI and when shortened, it would give the Roman numeral XVI (16). It is believed that this method for counting sheep was used by shepherds in Italy well into the 19th century.

Hand Signals Theory

This theory suggests that the Roman numbers represent the hand signals for counting.
In this theory, numbers one (I), two (II) and three (III) are equal to the fingers used when counting.
V (five) is the signal you see in between the thumb and fingers - when you open one hand and show all your five fingers.
The numbers six (VI), seven (VII) and eight (VIII) represent one hand showing five (V) and the other hand showing the equivalent numbers.
X (10) is two hands showing two fives with thumbs crossed, hence the shape ‘X’.
In later periods, the letter L was adapted to represent the number 50.
In the early days, the number 100 was usually represented by putting an ‘I’ on top of ‘X’; 500 and 1000 were written with a circle around 'V' and 'X', respectively. In later periods, Greek letters were modified and ‘C’ was adopted for 100, 'D' for 500, 'M' for 1000.
For representing greater values, lines (known as vinculum or virgula) were placed to indicate multiplication by by 1,000.

How to Read Roman Numerals

Roman numbers are read from left to right. They are formed by combining the seven letters based on addition and subtraction. The order of the numerals hints whether you need to subtract or add values.

Keeping in mind that greater values are usually written before the lower values, the two basic rules for reading Roman numerals are as follows:

If a letter comes before a letter of greater value, you subtract;
If one or more letters come after a letter of greater value, you add.

The first rule means that when a smaller value is placed before a larger value, the difference is the Roman number to be read. For example,

IV = 4
IX = 9
XL = 40
XC = 90
CM = 900

The second rule means that when a smaller value is placed after a larger value, the sum is the Roman number to be read. For example,

VII = 7
XII = 12
LIII = 53
CXIII = 113
LXXV = 75

Therefore, when you want to read or write a larger number, you need to take notice of these groupings to see the additions or subtractions.

For example, MCMXIX = 1919

This is because this number is grouped as follows:

M + CM + X + IX = 1000 + 900 + 10 + 9

You can use our online friendly tool to convert roman numerals to numbers.

Modern Uses of Roman Numerals

While they are not one of the numbering systems used in modern mathematics, Roman numbers are not only confined to history. They are still around us:

They are used on watches and clocks,
Book chapter headings and numbered points in print still use Roman numerals,
Subjects like chemistry, pharmaceuticals, seismology and theology might still apply Roman numerals when deemed necessary,
Roman numerals are used in order to refer to kings, queens, emperors and popes who share the same names (as in Louis XVI of France or Pope Benedict XVI),
In the film industry, Roman numerals might be used to indicate the year the film was produced,
Sporting competitions such as the Olympic Games or the Super Bowl represent how many times the games have been held by using Roman numerals.