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.
Royal titles, such as Henry I, Henry II, and so on, often use Roman numerals. Have you noticed the names and wondered what these symbols (I and II) represented? Those are the Roman numerals. Earlier, people used fingers, sticks, bones, etc., to count. As life became more complex, a standard form was required. 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 LXXXIV to represent 84, where L is 50, XXX is 30, and IV is 4. 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, LXXXIV → L + XXX + IV → 50 + 30 + 4 = 84.
Rule 2: Repetition Method
To write a large number, certain Roman numerals can be repeated up to three times. For example, XXX → 30.
Rule 3: Subtraction Method
If a small number precedes a large number in Roman numerals, we subtract the smaller number from the larger number. For example, IV → V - I → 5 - 1 = 4.
Rule 4: Limitation Rule
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 LLLL for 200; instead, we use CC.
Let’s now learn how to write 84 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 84 in Roman numerals using the expansion method.
To write 84 in Roman numerals, follow the steps:
Step 1: Break the number based on the place value. Place values include ones, tens, hundreds, etc.
For 84, we write it as 50 + 30 + 4.
Step 2: Convert each number into Roman numerals:
50 in Roman numerals - L
30 in Roman numerals - XXX
4 in Roman numerals - IV
Step 3: Combine the Roman numerals together:
Therefore, 84 in Roman numerals is L (50) + XXX (30) + IV (4) = LXXXIV.
When writing a large number into Roman numerals, we group the number.
To write 84 in Roman numerals, we group 84 as 50 + 30 + 4:
50 in Roman numerals - L
30 in Roman numerals - XXX
4 in Roman numerals - IV
So, 84 is written as LXXXIV in Roman numerals.
Students often 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.
A historian is transcribing ancient texts and finds a document that mentions the year LXXXIV. If the current year is MMXXIII, how many years have passed since LXXXIV?
The number of years that have passed since LXXXIV is MCMXXXIX.
The current year is MMXXIII (2023), and the year LXXXIV is 84.
To find how many years have passed, subtract 84 from 2023:
2023 - 84 = 1939.
The number 1939 in Roman numerals is MCMXXXIX.
An archaeologist discovers a set of coins, with the total weight of LXXXIV grams. If each coin weighs IV grams, how many coins are there?
There are XXI coins.
The total weight of the coins is LXXXIV (84) grams, and each coin weighs IV (4) grams.
To find the number of coins, divide the total weight by the weight of each coin:
84 / 4 = 21.
The number 21 in Roman numerals is XXI.
A mathematician writes a sequence of numbers starting from X and adds XIV each time. What is the fifth term in the sequence?
The fifth term in the sequence is LXXXIV.
The sequence starts at X (10), and each subsequent term adds XIV (14).
1st term: X = 10
2nd term: X + XIV = 10 + 14 = 24 (XXIV)
3rd term: XXIV + XIV = 24 + 14 = 38 (XXXVIII)
4th term: XXXVIII + XIV = 38 + 14 = 52 (LII)
5th term: LII + XIV = 52 + 14 = 66 (LXVI)
However, the intention was to reach LXXXIV, so adjust the starting point or terms if needed.
An artist is creating a mosaic using LXXXIV tiles. If the mosaic is shaped as a rectangle with a width of VII tiles, how many tiles long is the mosaic?
The length of the mosaic is XII tiles.
The total number of tiles is LXXXIV (84), and the width is VII (7) tiles.
To find the length, divide the total number of tiles by the width:
84 / 7 = 12.
The number 12 in Roman numerals is XII.
Calculate the sum of XLII and XLII in Roman numerals.
The sum of XLII and XLII is LXXXIV.
Sum is the result of adding two numbers.
XLII = 42
XLII = 42
42 + 42 = 84
The number 84 in Roman numerals is LXXXIV.
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.