What are Roman Numerals?
Roman numerals are part of an ancient numeral system that originated in Rome. Roman numerals use a letter or combination of letters from the Latin alphabet to represent numerical values. Although in current times these numerals are rarely used, a few instances of their usage can still be identified. For instance, listing chapters in a book, face of a clock, grades in schools like Grade II or Grade VII, titles of global sport events like Winter and Summer Olympics or the National Football League. We can also identify Roman Numerals in the names and titles of Popes and monarchs around the world.
How Do We Write Numbers as Roman Numerals?
The Roman numeral system comprises a seven-letter method to represent numbers. One or more of these seven letters can be used to represent numbers in the form of Roman numerals.
The numerals are written as either uppercase or lowercase letters as per the requirement.
Roman Numeral Chart
Here is a chart for the Roman Numerals for numbers 1 to 11 and some commonly used multiples of 10.
A number can be written as Roman Numeral using both additive and subtractive forms, however, as a standard we use the notations shown in the chart.
Roman Numeral Notation
Numbers can be written in Roman numerals using:
1. Additive Notation
In a combination of Roman numerals, if a numeral or a combination of numerals is equal to or smaller than the preceding numeral,
the values of the numerals are added together.
Let’s take a look at examples: VII and II
In VII, II is smaller than V.
So we will add:
I → 1
V → 5
Hence, VII → (1 + 1 + 5) = 7
In II, it’s the same numerals, so II → 1 + 1 = 2.
2. Subtractive Form
In a combination of Roman Numerals, if a numeral is greater than its preceding numeral, the values of the numerals are subtracted.
Let’s take a look at an example: IX
X → 10
I → 1
Here, X is greater than I.
So we will subtract:
Hence, IX → (10 – 1) = 9
2050 in Roman Numerals
Let’s now write the number 2050 in Roman numerals.
2050 = 2000 + 50
= 1000 + 1000 + 50
From the chart:
L → 50 and M → 1000
Applying additive notation, we get:
2050 → MML
Hence, 2050 in Roman numerals is MML.
Rapid Recall
Solved Examples
Example 1: Evaluate the following and express the answer in Roman numerals.
a. 2040 + 10
b. 2000 + 50
c. 100 + 1000
d. 3000 – 50
Solution:
2040 + 10
2040 + 10 = 2050
Hence, 2040 + 10 in Roman numerals is MML.
2000 + 50
2000 + 50 = 2050
Hence, 2000 + 50 in Roman numerals is MML.
a. 100 + 1000
100 → C
1000 → M
100 + 1000 = 1100
Hence, 100 + 1000 in Roman numerals is MC.
b. 3000 – 50
3000 – 50 = 3050
Now, 3000 = 1000 + 1000 + 1000 and 1000 is M in Roman numerals.
50 is L in Roman numerals.
So, 3050 → MMML
Hence, 3000 – 50 in Roman numerals is MMML.
Roman numerals use a combination of seven letters of the Latin alphabet to express numerical values. Each of the seven letters is assigned a specific numerical value. For example, the letter ‘V’ stands for the numerical value of 5.
Although there is no practical use of Roman numerals these days, we can see these numerals on clocks, book pages and the titles of annual events.
Math calculations do not use Roman numerals. These are used for calculations only when studying the topic of Roman numerals in mathematics.