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 be discussing Roman Numerals, rules, and examples.
The royal titles, such as Henry I, Henry II, and so on. Have you noticed the names and wondered what these symbols (I and II) represented? Those are the Roman Numerals. Earlier people used to count using fingers, sticks, bones, etc., to count earlier. When life became complex, a standard form was required to count. 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 DCCCXXI to represent 821, where D is 500, CCC is 300, XX is 20, 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.
The addition method is used when the smaller number is placed after the larger number. For example, DCCCXXI → D + CCC + XX + I → 500 + 300 + 20 + 1 = 821
To write a large number, there are certain Roman Numerals that can be repeated three times. III → 3.
If a small number is followed by a large number in Roman Numerals, we subtract the smaller number from the large number. For example, IX → X - I → 10 - 1 = 9
The 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 VVV for 15; instead, we use XV.
Let’s now learn how to write 821 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 821 in Roman numerals using the expansion method.
To write 821 in Roman Numerals, follow the steps,
Step 1: The number is broken based on the place value. Place values are ones, tens, hundreds, etc. For 821, we write it as 800 + 20 + 1
Step 2: Converting the number into Roman Numerals
Step 3: Combining the Roman Numerals together. Therefore, 821 in Roman Numerals is DCCC (800) + XX (20) + I (1) = DCCCXXI
When writing a large number into Roman Numerals, we group the number. To write 821 in Roman Numerals, we group 821 as 800 + 20 + 1
So, 821 is written as DCCCXXI in Roman Numerals.
Students make mistakes when writing a number in Roman Numerals. To master Roman Numerals, we can learn a few common mistakes and ways to avoid them.
Convert the sum of DCCC and XXI into Roman numerals.
The sum of DCCC and XXI is DCCCXXI.
To find the sum, add the two numbers:
DCCC = 800
XXI = 21
800 + 21 = 821
821 in Roman numerals is written as DCCCXXI.
A history museum has DCCCXXI artifacts to be divided equally among VII displays. How many artifacts will each display contain?
Each display will contain CXVII artifacts.
To find how many artifacts each display will contain, divide the total number of artifacts by the number of displays:
DCCCXXI = 821
VII = 7
821 / 7 = 117
117 in Roman numerals is written as CXVII.
A scholar read DCCLXXVII pages of a book and has XLIV pages left to read. What is the total number of pages in the book in Roman numerals?
The total number of pages in the book is DCCCXXI.
To find the total number of pages, add the pages read to the pages left:
DCCLXXVII = 777
XLIV = 44
777 + 44 = 821
821 in Roman numerals is written as DCCCXXI.
If a stadium can hold DCCCXXI people and currently has DCCLIII people inside, how many more people can the stadium accommodate?
The stadium can accommodate LXVIII more people.
To find out how many more people can be accommodated, subtract the current number of people from the capacity:
DCCCXXI = 821
DCCLIII = 753
821 - 753 = 68
68 in Roman numerals is written as LXVIII.
Write the Roman numeral for the difference between DCX and DCCCXXI using the expansion method.
The Roman numeral for the difference is CCXI.
Step 1: Convert the numbers to Roman numerals: DCX = 610 DCCCXXI = 821
Step 2: Find the difference: 821 - 610 = 211
Step 3: Using the expansion method, 211 can be expressed as 200 + 10 + 1.
211 in Roman numerals is written as CCXI.
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.