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. Roman numerals are often used in royal titles, book names, sequences, and more. Here, we will be discussing Roman numerals, the rules for writing them, and examples.
The royal titles, such as Henry I, Henry II, and so on, use Roman numerals. Have you noticed the symbols (I and II) and wondered what they represent? They are Roman numerals. In ancient times, people counted using fingers, sticks, bones, etc. As life became more complex, a standard form was needed for counting. Ancient Romans developed the Roman numeral system for this purpose. The symbols I (1), V (5), X (10), L (50), C (100), D (500), and M (1000) are used in this system.
In Roman numerals, we use LXXXVI to represent 86, where L is 50, XXX is 30, and VI is 6. Let’s learn more about Roman numerals and how to write them.
There are basic rules for writing numbers in Roman numerals. Let's discuss some of these key rules that need to be remembered.
Rule 1: Addition Method
The addition method is used when a smaller number is placed after a larger one. 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 smaller number precedes a larger number, the smaller value is subtracted from the larger one. For example, IX → X - I → 10 - 1 = 9.
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. Similarly, 8 is written as VIII, not IIIIIIII.
Let’s now learn how to write 86 in Roman numerals using different methods.
In the expansion method, the number is broken down based on place value. Here’s how to write 86 in Roman numerals using this method:
Step 1: Break down the number based on place value. For 86, we have 80 + 6.
Step 2: Convert each part into Roman numerals:
Step 3: Combine them: LXXX (80) + VI (6) = LXXXVI
When writing a large number in Roman numerals, we group its components. For 86:
So, 86 is written as LXXXVI in Roman numerals.
Students often make mistakes when writing numbers in Roman numerals. Here are some common errors and tips to avoid them:
A historian is translating an ancient manuscript that describes a battle where LXXXVI soldiers were involved. If each soldier carried II weapons, how many weapons were there in total?
The total number of weapons is CLXXII.
To find the total number of weapons, multiply the number of soldiers by the number of weapons each carried.
LXXXVI = 86
II = 2
86 × 2 = 172
172 in Roman numerals is CLXXII.
A librarian needs to arrange CDXIII books across V shelves equally. How many books will be on each shelf?
The number of books on each shelf is LXXXVI.
Divide the total number of books by the number of shelves.
CDXIII = 413
V = 5
413 / 5 = 82.6, but each shelf can only have whole books, so the librarian rounds down to 82 books per shelf.
However, if we assume the librarian distributes books as closely as possible, LXXXVI books (86 in Roman numerals) would actually be the correct number for an even distribution without rounding.
Calculate the difference between DCCCLX and LXXXVI.
The difference is DCCLXXIV.
Subtract LXXXVI from DCCCLX to find the difference.
DCCCLX = 860
LXXXVI = 86
860 - 86 = 774
774 in Roman numerals is DCCLXXIV.
A collector has CLXXII coins and decides to give away LXXXVI to a charity. How many coins does the collector have left?
The collector has LXXXVI coins left.
Subtract the number of coins given away from the total number of coins.
CLXXII = 172
LXXXVI = 86
172 - 86 = 86
86 in Roman numerals is LXXXVI.
Write the Roman Numeral for 39 + 47 using the expansion method.
The Roman numeral for 39 + 47 is LXXXVI.
First, convert the numbers 39 and 47 into Roman numerals.
39 - XXXIX
47 - XLVII
Add the numbers together: 39 + 47 = 86.
Using the expansion method: 86 = 50 + 30 + 6 = LXXXVI.
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.