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 used. Roman numerals are commonly seen in royal titles, book names, sequences, and more. Here we will be discussing Roman numerals, their rules, and examples.
The royal titles, such as Henry I, Henry II, and so on, use Roman numerals. Have you noticed these symbols (I and II) and wondered what they represent? Those are Roman numerals. In ancient times, people used fingers, sticks, bones, etc., to count. As life became more complex, a standard form was required for counting. 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 used for counting.
In Roman numerals, we use C to represent 100. 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 the smaller number is placed after the larger number. For example, VI → V + I → 5 + 1 = 6.
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 small number is followed by a large 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 don't write VV for 10; instead, we use X.
Let’s learn how to write 100 in Roman numerals using different methods.
In the expansion method, based on the place value, the number is broken down. Here’s how to write 100 in Roman numerals using the expansion method:
Step 1: Break down the number based on place value. For 100, we have it as 100.
Step 2: Convert the number into Roman numerals:-
100 in Roman numeral - C
Therefore, 100 in Roman numeral is C.
When writing a number in Roman numeral form, we group the number. To write 100 in Roman numeral, we use the symbol directly:
100 in Roman numeral - C
So, 100 is written as C in Roman numerals.
Mistakes can occur when writing numbers in Roman numerals. Here are some common mistakes and ways to avoid them:
A historian is categorizing artifacts and finds that each category contains the same number of artifacts. If there are a total of C artifacts divided equally among IV categories, how many artifacts are in each category?
The number of artifacts in each category is XXV.
C = 100
IV = 4
100 / 4 = 25
25 in Roman numerals is XXV.
An architect is designing a layout that requires combining two sections of a building. If the first section is LXV square meters and the second section is XXXV square meters, what is the total area of the combined sections?
The total area of the combined sections is C.
LXV = 65
XXXV = 35
65 + 35 = 100
100 in Roman numerals is C.
An artist is creating a mural that requires exactly 100 tiles. If the artist has already placed XLV tiles, how many more tiles are needed to complete the mural?
The artist needs LV more tiles.
C = 100
XLV = 45
100 - 45 = 55
55 in Roman numerals is LV.
A librarian has a collection of C books and wants to distribute them equally on X shelves. How many books will each shelf have?
Each shelf will have X books.
C = 100
X = 10
100 / 10 = 10
10 in Roman numerals is X.
A math teacher asks students to convert the sum of LIII and XLVII into Roman numerals. What is the sum in Roman numerals?
The sum of LIII and XLVII is C.
LIII = 53
XLVII = 47
53 + 47 = 100
100 in Roman numerals is C.
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.