Roman Numerals

Roman Numerals

You might be surprised to discover that $800$ years ago, the common numbers we use today $(0,1,2,3,4...)$ were not used, but Roman numerals were used instead!

Basic Roman Numerals

The number $1$  - $I$
The number $2$ - $II$
The number $3$ - $III$
The number $5$ - $V$
The number $10$ - $X$

If the symbol is written to the right of a larger one, it is added to the previous one to reach the total number.
If the symbol is written to the left of a larger one, it is subtracted from the previous one to reach the total number.
To write Roman numerals from $1-12$, we will do it with sums and subtractions of the basic numbers.

Roman Numerals

You might be surprised to discover that $800$ years ago, the common numbers we use today $(0,1,2,3,4...)$ were not used, but Roman numerals were used instead!
In this article, you will learn to identify Roman numerals, to write them from $1-12$ and the particularities of the Roman numeral system.
Shall we start?

To identify Roman numerals $1-12$ you must know the representation of their basic figures:

The figure $1$  - $I$
The figure $2$ - $II$
The figure $3$ - $III$
The figure $5$ - $V$
The figure $10$ - $X$

The particularities of Roman numerals are

If we write a symbol to the right of a larger one, it must be added to the larger one.
If we write a symbol to the left of a larger one, it must be subtracted from the larger one.
Using only the base symbols written previously, by writing them in the correct order and finding the corresponding addition or subtraction, we can reach all the Roman numerals from $1-12$.

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How is that? Let's look at some examples.

How would we write the number 4?

We know that the number $4$ is, in fact, $5-1$
Therefore, according to the Roman system, if we take the Roman symbol $5$ - $V$ and, to its left, we place the symbol $1$-> $I$, we arrive at the number $4$.
Since placing a lower number to the left of the other given number gets us to the desired number.
That is, $4$ in Roman numerals is -> $IV$

Imagine that, between the $V$ that represents the $5$ and the $I$ that represents the $1$ there is a small minus sign.
Likewise, we could have represented the $4$ as $3+1$
And thus, according to the peculiarities of the Roman system, we have to place the lower number to the right of another to add it and arrive at the desired number. That is $IIII$

Now let's write the number 6

The number $6$ can be represented in the simplest way with two symbols $5+1$
In order to add them, we must place the $1$ to the right of the $5$ the given number:
$6$ in Roman numerals will look like this: $VI$

How would we write the number 7?

Note that, for the representation of numbers we use the basic symbols that we wrote previously.
The $7$ can be represented with $5+2$
According to the system, the $2$ must be placed to the right of the $5$ so that they add up:
$7$ in Roman numerals will look like this $VII$

How would we write the number 8?

The simplest way to write the $8$ is with the basic symbols: $5+3$
So that we can add them, we must place the $3$ to the right of the five.
$8$ in Roman numerals will look like this $VIII$

How would we write the number 9?

Notice that, one of the given numbers is $10$ which is represented by $X$.
We can write $9$ as $10-1$
For there to be a subtraction, we must place the number one to the left of the number $10$.
$9$ in Roman numerals will look like this $IX$

How would we write the number 11?

The $11$ can be represented with $10+1$
The addition occurs by writing the smaller figure to the right of a larger one, then,
$11$ in Roman numerals will look like this $XI$

How would we write the number 12?

The $12$ can be represented as $10+2$
The addition will occur if we place the lower figure to the right.
$12$ in Roman numerals will look like this $XII$