Last updated on May 26th, 2025
Roman numerals are a way of expressing numbers using specific symbols: I, V, X, L, C, D, and M. They are often used in royal titles, book titles, sequences, and more. Here, we will discuss Roman numerals, their rules, and examples.
Roman numerals are used in various contexts, such as royal titles like Henry I, Henry II, and so on. You might have noticed the numerals and wondered what these symbols (I, II) represented. Those are Roman numerals. In ancient times, people counted using fingers, sticks, bones, etc. As life grew more complex, a standard form was required for counting. The ancient Romans used the Roman numeral system for this purpose. The symbols I (1), V (5), X (10), L (50), C (100), D (500), and M (1000) are used to represent numbers.
In Roman numerals, we use CXXV to represent 125. Here, C is 100, X is 10, another X is 10, and V is 5. Let’s learn more about Roman numerals and how we write them.
There are certain basic rules to write a number in Roman numerals. In this section, let’s discuss some basic rules that need to be remembered when writing a number in Roman numerals.
Rule 1: Addition Method
The addition method is used when a smaller number is placed after a larger number. For example, CXXV → C + X + X + V → 100 + 10 + 10 + 5 = 125.
Rule 2: Repetition Method
To write a large number, certain Roman numerals can be repeated up to three times. For example, XXX → 30.
Rule 3: Subtraction Method
If a small number precedes a large number in Roman numerals, we subtract the smaller number from the larger number. For example, XC → X - C → 100 - 10 = 90.
Rule 4: Limitation Rule
The symbols cannot be repeated more than three times, and some symbols like V, L, and D cannot be repeated. For example, we don't write VV for 10; instead, we use X. For 8, we write VIII, not IIIIIIII.
Let’s now learn how to write 125 in Roman numerals. Follow these methods to write the number in Roman numerals.
In the expansion method, based on the place value, the number is broken down. In this section, we will learn how to write 125 in Roman numerals using the expansion method.
To write 125 in Roman numerals, follow the steps:
Step 1: Break down the number based on place value. For 125, we write it as 100 + 20 + 5.
Step 2: Convert the numbers into Roman numerals:
100 in Roman numeral — C
20 in Roman numeral — XX
5 in Roman numeral — V
Step 3: Combine the Roman numerals together. Therefore, 125 in Roman numeral is C (100) + XX (20) + V (5) = CXXV.
When writing a large number in Roman numerals, we group the number. To write 125 in Roman numerals, we group 125 as 100 + 20 + 5:
100 in Roman numeral — C
20 in Roman numeral — XX
5 in Roman numeral — V
So, 125 is written as CXXV in Roman numerals.
Students often make mistakes when writing numbers in Roman numerals. To master Roman numerals, we can learn a few common mistakes and ways to avoid them.
A historian is deciphering an ancient text that mentions two armies, one with CL soldiers and another with LXXV soldiers. Find the total number of soldiers when the two armies combine.
The total number of soldiers is CCXXV.
In Roman numerals, CL is 150 and LXXV is 75. Adding them together gives 150 + 75 = 225. 225 in Roman numerals can be written as CCXXV.
An archaeologist discovers a set of ancient coins, CXXV in total, and wants to distribute them equally among V artifacts. How many coins will each artifact receive?
Each artifact will receive XXV coins.
To find the number of coins per artifact, divide the total number of coins by the number of artifacts: CXXV / V.
CXXV = 125
V = 5
Therefore, 125 / 5 = 25.
25 in Roman numerals is XXV.
A library has CXXV scrolls and plans to acquire another L scrolls. What will be the total number of scrolls in the library?
The total number of scrolls will be CLXXV.
The sum is the result of adding two numbers.
CXXV = 125
L = 50
125 + 50 = 175
175 in Roman numerals is CLXXV.
A merchant has CXL apples and sells XV apples. How many apples remain with the merchant?
The number of apples remaining is CXXV.
The difference is the result of subtracting one number from another.
CXL = 140
XV = 15
140 15 = 125
125 in Roman numerals is CXXV.
Express the sum of 75 and 50 in Roman numerals using the expansion method.
The Roman numeral for 75 + 50 is CXXV.
First, convert the numbers 75 and 50 into Roman numerals:
75 LXXV
50 L
Add the numbers together: 75 + 50 = 125
Using the expansion method: 125 = 100 + 20 + 5 = CXXV.
Hiralee Lalitkumar Makwana has almost two years of teaching experience. She is a number ninja as she loves numbers. Her interest in numbers can be seen in the way she cracks math puzzles and hidden patterns.
: She loves to read number jokes and games.