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. Roman Numerals are often found in royal titles, book chapters, sequences, and more. Here we will discuss Roman Numerals, their rules, and examples.
Royal titles, such as Henry I, Henry II, and so on, often incorporate Roman Numerals. You might have noticed these symbols (I and II) and wondered what they represented. These are Roman Numerals. In ancient times, people used fingers, sticks, bones, etc., to count.
As life became more complex, a standardized form was needed. The ancient Romans used the Roman Numeral system for counting. The symbols I (1), V (5), X (10), L (50), C (100), D (500), and M (1000) are used.
In Roman Numerals, we use CCCLXXI to represent 371, where C is 100, L is 50, X is 10, and I is 1. 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, CCCLXXI → C + C + C + L + X + X + I → 100 + 100 + 100 + 50 + 10 + 10 + 1 = 371
Rule 2: Repetition Method
Certain Roman Numerals can be repeated up to three times. For example, CCC → 100 + 100 + 100 = 300.
Rule 3: Subtraction Method
If a smaller number is followed by a larger number in Roman Numerals, we subtract the smaller number from the larger number. For example, XL → L - X → 50 - 10 = 40
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 LLL for 150. Instead, we use CL.
Let’s now learn how to write 371 in Roman Numerals. Follow these methods to write the number in Roman Numerals.
In the expansion method, the number is broken down based on place value. Here’s how to write 371 in Roman numerals using the expansion method:
1. Break down 371 by place value: 300 + 70 + 1
2. Convert each number into Roman Numerals:
- 300 in Roman Numerals — CCC
- 70 in Roman Numerals — LXX
- 1 in Roman Numerals — I
3. Combine them: CCC + LXX + I = CCCLXXI
When writing a large number into Roman Numerals, we group the number. To write 371 in Roman Numerals, we group it as 300 + 70 + 1:
- 300 in Roman Numerals — CCC
- 70 in Roman Numerals — LXX
- 1 in Roman Numerals — I
So, 371 is written as CCCLXXI 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 the ways to avoid them.
A historian is cataloging ancient artifacts and finds a collection of CCCLXXI items. She wants to display them equally across XIII exhibition halls. How many items will be in each hall?
Each hall will have XXIX items.
To find the number of items in each hall, divide the total number of items by the number of halls.
CCCLXXI = 371
XIII = 13
371 / 13 = 29
29 in Roman numerals is XXIX.
An architect is designing a series of arches that total CCCLXXI feet in height. Each arch is to be XXI feet tall. How many arches can the architect build?
The architect can build XVII arches.
To determine how many arches can be built, divide the total height by the height of each arch.
CCCLXXI = 371
XXI = 21
371 / 21 = 17
17 in Roman numerals is XVII.
A librarian has CCXL books and receives an additional CXXXI books. What is the total number of books in Roman numerals?
The total number of books is CCCLXXI.
Add the numbers to get the total.
CCXL = 240
CXXXI = 131
240 + 131 = 371
371 in Roman numerals is CCCLXXI.
A treasure map lists two locations: one at CLX miles and another at CCXI miles from a starting point. What is the difference in miles between the two locations in Roman numerals?
The difference is LI.
Subtract to find the difference between the two locations.
CCXI = 211
CLX = 160
211 - 160 = 51
51 in Roman numerals is LI.
An engineer needs to convert the sum of 171 and 200 into Roman numerals using the expansion method. What is the result?
The Roman numeral for 171 + 200 is CCCLXXI.
First, convert the numbers to Roman numerals, then add them.
171 = CLXXI
200 = CC
Add the numbers together: 171 + 200 = 371
Using expansion method: 371 = 300 + 70 + 1 = CCCLXXI.
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.