Last updated on May 26th, 2025
Roman numerals are a way of expressing numbers using symbols. I, V, X, L, C, D, and M are the symbols we use. Roman numerals are used in royal titles, book names, sequences, and so on. Here we will discuss Roman numerals, rules, and examples.
Royal titles, such as Henry I, Henry II, and so on, often use Roman numerals. Have you noticed the names and wondered what these symbols (I and II) represented?
Those are Roman numerals. Earlier, people used fingers, sticks, bones, etc., to count. As life became more complex, a standard form was required. Ancient Romans used the Roman numeral system to count. I (1), V (5), X (10), L (50), C (100), D (500), and M (1000) are the symbols we use to count.
In Roman numerals, we use CXLIX to represent 149, where C is 100, XL is 40, and IX is 9. 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.
The addition method is used when a smaller number is placed after a larger number. For example, VI → V + I → 5 + 1 = 6.
To write a large number, certain Roman numerals can be repeated up to three times. III → 3.
If a smaller number precedes a larger number in Roman numerals, we subtract the smaller number from the larger number. For example, IX → X - I → 10 - 1 = 9.
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, and for 8, we write VIII, not IIIIIIII.
Let’s now learn how to write 149 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 149 in Roman numerals using the expansion method.
To write 149 in Roman numerals, follow the steps:
Step 1: Break the number based on place value. The place values are ones, tens, hundreds, etc.
For 149, we write it as 100 + 40 + 9.
Step 2: Convert the number into Roman numerals:
- 100 in Roman numerals — C
- 40 in Roman numerals — XL
- 9 in Roman numerals — IX
Step 3: Combine the Roman numerals together.
Therefore, 149 in Roman numerals is C (100) + XL (40) + IX (9) = CXLIX.
When writing a large number into Roman numerals, we group the number. To write 149 in Roman numerals, we group 149 as 100 + 40 + 9.
- 100 in Roman numerals — C
- 40 in Roman numerals — XL
- 9 in Roman numerals — IX
So, 149 is written as CXLIX 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 XIV ancient artifacts from each of the X regions. How many artifacts does the historian have in total?
The total number of artifacts is CXL.
The total number of artifacts is calculated by multiplying the number of artifacts per region by the number of regions.
XIV = 14
X = 10
14 × 10 = 140
140 in Roman Numerals is CXL.
A librarian needs to arrange CLXXVIII scrolls evenly across XIII shelves. How many scrolls will be on each shelf?
Each shelf will have XIV scrolls.
To find the number of scrolls per shelf, divide the total number of scrolls by the number of shelves.
CLXXVIII = 178
XIII = 13
178 / 13 = 14
14 in Roman Numerals is XIV.
Calculate the sum of C and XLIX.
The sum of C and XLIX is CXLIX.
The sum is the result of adding two numbers.
C = 100
XLIX = 49
100 + 49 = 149
149 in Roman Numerals is CXLIX.
What is the difference between CLX and XI?
The difference between CLX and XI is CXLIX.
The difference of two numbers is the value we get when subtracting one number from the other.
CLX = 160
XI = 11
160 - 11 = 149
149 in Roman Numerals can be written as CXLIX.
Write the Roman Numeral for 100 + 49 using the expansion method.
The Roman numeral for 100 + 49 is CXLIX.
Step 1: Convert the numbers 100 and 49 into Roman numerals.
100 - C
49 - XLIX
Add the numbers together: 100 + 49 = 149
Using the expansion method: 149 = 100 + 40 + 9 = C + XL + IX = CXLIX.
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.