Last updated on May 26th, 2025
Roman numerals are a way of expressing numbers using symbols. The symbols I, V, X, L, C, D, and M are used in this system. Roman numerals are found in royal titles, book names, sequences, and more. In this discussion, we will explore Roman numerals, their rules, and examples.
Royal titles like Henry I, Henry II, and so forth, use Roman numerals. The symbols (I and II) represent numbers, and these are Roman numerals. In ancient times, people counted using fingers, sticks, bones, etc. As life became more complex, a standard form of counting was needed. The ancient Romans developed 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 in this system.
In Roman numerals, we use CXXXI to represent 131, where C is 100, X is 10, and I is 1. Let’s learn more about Roman numerals and how to write them.
There are certain basic rules to write numbers in Roman numerals. In this section, let’s discuss some basic rules that need to be remembered when writing numbers in Roman numerals.
Rule 1: Addition Method
The addition method is used when a smaller number is placed after a larger number. For example, CXXXI → C + X + X + I → 100 + 10 + 10 + 1 = 131.
Rule 2: Repetition Method
To write larger numbers, certain Roman numerals can be repeated up to three times. For example, XXX → 30.
Rule 3: Subtraction Method
If a smaller number is placed before a larger number, we subtract the smaller number from the larger number. For example, IX → X - I → 10 - 1 = 9.
Rule 4: Limitation Rule
Symbols cannot be repeated more than three times, and some symbols like V, L, and D cannot be repeated. For example, we won't write VV for 10; instead, we use X. For 8, we write VIII, not IIIIIIII.
Let’s now learn how to write 131 in Roman numerals. Follow these methods to write the number in Roman numerals.
To write 131 in Roman numerals, follow these steps:
Step 1: Break the number based on place value: ones, tens, hundreds, etc.
For 131, we write it as 100 + 30 + 1.
Step 2: Convert each number into Roman numerals:
100 in Roman numerals — C
30 in Roman numerals — XXX
1 in Roman numerals — I
Step 3: Combine the Roman numerals together:
Therefore, 131 in Roman numerals is C (100) + XXX (30) + I (1) = CXXXI.
When writing a large number into Roman numerals, we group the number.
To write 131 in Roman numerals, we group 131 as 100 + 30 + 1.
100 in Roman numerals — C
30 in Roman numerals — XXX
1 in Roman numerals — I
So, 131 is written as CXXXI 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 cataloging CXXIV ancient coins, each with an inscription of VII. How many inscriptions are there in total?
The total number of inscriptions is DCCCXLVIII.
To find the total number of inscriptions, multiply the number of coins by the number of inscriptions per coin.
CXXIV = 124
VII = 7
124 × 7 = 868
868 in Roman Numerals can be written as DCCCXLVIII.
An art gallery has a collection of CCCCLXXVIII paintings, each grouped into sets of XXIX. Calculate how many sets there are.
The number of sets is XVI.
To find the number of sets, divide the total number of paintings by the number of paintings per set.
CCCCLXXVIII = 478
XXIX = 29
478 ÷ 29 = 16
16 in Roman Numerals can be written as XVI.
Calculate the sum of CLXI and LXX.
The sum of CLXI and LXX is CCXXXI.
Sum is the result of adding two numbers.
CLXI = 161
LXX = 70
161 + 70 = 231
231 in Roman Numerals is CCXXXI.
What is the difference between CCXL and CIX?
The difference between CCXL and CIX is CXXXI.
The difference of two numbers is the value we get when subtracting one number from the other.
CCXL = 240
CIX = 109
240 - 109 = 131
131 in Roman Numerals can be written as CXXXI.
Write the Roman Numeral for 83 + 48 using the expansion method.
The Roman numeral for 83 + 48 is CXXXI.
Step 1: First convert the numbers 83 and 48 into Roman numerals.
83 - LXXXIII
48 - XLVIII
Add the numbers together: 83 + 48 = 131
Using expansion method: 131 = 100 + 30 + 1 = CXXXI.
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.