Last updated on May 26th, 2025
Roman numerals are a method of expressing numbers using specific symbols: I, V, X, L, C, D, and M. They are commonly used in royal titles, book names, sequences, and more. Here, we will explore Roman numerals, their rules, and examples.
You've probably seen royal titles like Henry VIII and wondered what the symbols represent. These are Roman numerals. In ancient times, people counted using fingers, sticks, bones, etc. As life became more complex, a standardized form was needed for counting, which led to the Roman numeral system. The symbols include I (1), V (5), X (10), L (50), C (100), D (500), and M (1000).
In Roman numerals, we use CCCXVII to represent 317. Here, CCC is 300, X is 10, V is 5, and II is 2. Let's learn more about Roman numerals and how we write them.
There are basic rules to write a number in Roman numerals. Let's discuss these rules that are crucial when writing numbers in Roman numerals.
Rule 1: Addition Method
The addition method is used when a smaller number is placed after a larger number. For example, XVII → X + V + II → 10 + 5 + 2 = 17.
Rule 2: Repetition Method
Certain Roman numerals can be repeated up to three times. For example, CCC → 300.
Rule 3: Subtraction Method
If a smaller number precedes a larger number, we subtract the smaller number. For example, IV → V - I → 5 - 1 = 4.
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. For 8, we write VIII, not IIIIIIII.
Let’s learn how to write 317 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.
To write 317 in Roman numerals, follow these steps:
Step 1: Break down the number based on place value: hundreds, tens, and ones.
For 317, we write it as 300 + 10 + 7.
Step 2: Convert the number into Roman numerals:
- 300 in Roman numerals — CCC
- 10 in Roman numerals — X
- 7 in Roman numerals — VII
Step 3: Combine them into Roman numerals.
Therefore, 317 in Roman numerals is CCC (300) + X (10) + VII (7) = CCCXVII.
When writing a large number in Roman numerals, we group the number.
To write 317 in Roman numerals, group 317 as 300 + 10 + 7:
- 300 in Roman numerals — CCC
- 10 in Roman numerals — X
- 7 in Roman numerals — VII
So, 317 is written as CCCXVII in Roman numerals.
Students often make mistakes when writing numbers in Roman numerals. Here are some common mistakes and ways to avoid them:
A historian found a chest containing CCCXVII ancient coins. If he distributes them equally among VII researchers, how many coins will each researcher receive?
Each researcher will receive XLV coins.
To find the number of coins each researcher gets, we divide the total number of coins by the number of researchers.
That is CCCXVII / VII.
CCCXVII = 317
VII = 7
Therefore, CCCXVII / VII = 317 / 7 = 45.
45 in Roman numerals can be written as XLV.
Find the sum of CCLX and LVII.
The sum of CCLX and LVII is CCCXVII.
The sum is the result of adding two numbers.
CCLX = 260
LVII = 57
260 + 57 = 317
317 in Roman numerals is CCCXVII.
The sum of CCLX and LVII is CCCXVII.
A teacher divides a total of CMXV books among XXIX students. Determine how many books each student receives.
Each student will receive XXXI books.
To find the number of books each student gets, divide the total number of books by the number of students.
CMXV = 915
XXIX = 29
915 / 29 = 31
31 in Roman numerals is XXXI.
What is the difference between DCCC and CCCXVII?
The difference between DCCC and CCCXVII is CDLXXXIII.
The difference of two numbers is the value obtained by subtracting one number from the other.
DCCC = 800
CCCXVII = 317
800 - 317 = 483
483 in Roman numerals is CDLXXXIII.
Write the Roman Numeral for 150 + 167 using the expansion method.
The Roman numeral for 150 + 167 is CCCXVII.
Step 1: First convert the numbers 150 and 167 into Roman numerals.
150 = CL
167 = CLXVII
Add the numbers together: 150 + 167 = 317
Using expansion method: 317 = 300 + 10 + 7 = CCCXVII.
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.