Roman Numerals 1 to 15
2026-02-28 10:41 Diff
https://brightchamps.com/en-us/math/numbers/roman-numerals-1-to-15

Roman Numerals follow rules to make sure the number is written correctly. Here are some main rules given below:

Rule 1: Addition Method

Rule 2: Repetition Method

Rule 3: Subtraction Method

Rule 4: Limitation Rule

Rule 1: Addition Method

In Roman Numerals, if the smaller numeral comes after the large numeral, then we need to add their values.

Example: If the given number is VIII. We can see that the number V refers to 5 and the other number refers to 3. So in this, the smaller numeral is after the large numeral, so we need to add the 5 and 3 to get the value 8.

Rule 2: Repetition Method

The Roman Numeral can be repeated up to three times to increase its value. The numbers cannot be repeated after three times. Only symbols like I and X can be repeated and V cannot be repeated.

Example: III = 1 + 1 + 1 = 3, repeating the numeral I for the fourth time is not allowed.

Rule 3: Subtraction Method

If the smaller numeral comes before the large numeral, then we need to subtract the smaller numeral from the larger numeral to get the number. There are two rules in subtraction, they are, I can be subtracted from V and X.


Example: In the number IV. Here, V is the biggest numeral and I is the smallest numeral. As we see that the smaller numeral is before the larger numeral, we need to subtract to get the number. V(5) - I(1) = IV(4).

Rule 4: Limitation Rule

Roman Numerals consist of several limitations, they are: A numeral cannot be repeated more than three times.

For example, III (3) cannot be repeated more than 3 times, instead, we use IV for writing 4. Subtraction cannot be done with non-pair numbers.

For example, XI here X(10) - I(1) gives IX is applicable but IC is not applicable. Only one subtraction can be allowed in one numeral.

For example, IX(9), X(10) - I(1) is applicable to get 9 but IXX is not applicable to get the number 8.