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 various contexts such as royal titles, book names, sequences, and more. Here we will be discussing Roman numerals, the rules governing them, and examples.
Roman numerals are used in various contexts, such as royal titles. Have you ever seen names like Henry I or Henry II and wondered what these symbols represented? They are Roman numerals.
In ancient times, people used fingers, sticks, bones, etc., to count. As life became more complex, a standard form was needed. The ancient Romans developed the Roman numeral system. The symbols I (1), V (5), X (10), L (50), C (100), D (500), and M (1000) are used.
In Roman numerals, we use CDVII to represent 407, where CD is 400 and VII is 7. Let’s learn more about Roman numerals and how we write them.
There are certain basic rules to write a number in Roman numerals. Here, we will 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 the larger number. For example, VII → V + I + I → 5 + 1 + 1 = 7.
To write certain numbers, specific Roman numerals can be repeated up to three times. For example, III → 3.
If a smaller number is placed before a larger number, we subtract the smaller number from the larger number. For example, IV → V - I → 5 - 1 = 4.
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.
Let’s learn how to write 407 in Roman numerals using different methods.
In the expansion method, the number is broken down based on place value. Here’s how to write 407 in Roman numerals using this method:
Step 1: Break the number based on place value into hundreds and ones. For 407, we write it as 400 + 7.
Step 2: Convert each part into Roman numerals.
400 in Roman numerals — CD
7 in Roman numerals — VII
Step 3: Combine the Roman numerals. Therefore, 407 in Roman numerals is CD (400) + VII (7) = CDVII
When writing a large number in Roman numerals, we group the number. To write 407 in Roman numerals, we group 407 as 400 + 7.
So, 407 is written as CDVII in Roman numerals.
Students often make mistakes when writing numbers in Roman numerals. To master Roman numerals, we can learn from common mistakes and how to avoid them.
Calculate the sum of CD and VII.
The sum of CD and VII is CDVII.
To find the sum, add the two numbers together.
CD = 400
VII = 7
400 + 7 = 407
407 in Roman Numerals is CDVII.
A historian is cataloging CDVII artifacts equally among XIII exhibitions. How many artifacts will each exhibition receive?
Each exhibition will receive XXXI artifacts.
Divide the total number of artifacts by the number of exhibitions.
CDVII = 407
XIII = 13
407 ÷ 13 = 31
31 in Roman numerals is XXXI.
What is the product of XXIX and XIV translated into Roman numerals?
The product of XXIX and XIV is CDVI.
First, convert the Roman numerals into numbers and multiply them.
XXIX = 29
XIV = 14
29 × 14 = 406
406 in Roman numerals is CDVI.
If a library has DLX books and removes CXLIII books, how many books remain?
The library will have CDVII books remaining.
Subtract the number of books removed from the total number of books.
DLX = 560
CXLIII = 143
560 - 143 = 417
417 in Roman numerals is CDXVII.
Convert the result of the subtraction of CCCXL from DCCXLVII to Roman numerals.
The result of the subtraction is CDVII.
Subtract the smaller number from the larger number.
DCCXLVII = 747
CCCXL = 340
747 - 340 = 407
407 in Roman numerals is CDVII.
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.