18 in Roman Numerals

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. 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 XVIII to represent 18, here X is 10, V is 5, and III is 3. 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, then it is the addition method. For example, XVIII → X + V + III → 10 + 5 + 3 = 18

Rule 2: Repetition Method

To write a large number, there are certain Roman Numerals that can be repeated up to three times. III → 3.

Rule 3: Subtraction Method

If a small number is followed by a large number in Roman Numerals, we subtract the smaller number from the large number; it is a subtraction method. For example, IX → X - I → 10 - 1 = 9

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 VV for 10; instead, we use X. For 8, we write VIII, not IIIIIIII.
 

Let’s now learn how to write 18 in Roman Numerals. Follow these methods to write the number in Roman Numerals.

By Expansion Method  
By Grouping Method
 

In the expansion method, based on the place value, the number is broken down. In this section, we will learn how to write 18 in Roman numerals using the expansion method.
 

To write 18 in Roman Numerals, follow the steps:

Step 1: The number is broken based on the place value. Place value that is ones, tens, hundreds, etc.

For 18, we write it as 10 + 5 + 3.  

Step 2: Converting the number into Roman Numerals  

10 in Roman Numerals — X  
5 in Roman Numerals — V  
3 in Roman Numerals — III  

Step 3: Combining the Roman Numerals together.

 
Therefore, 18 in Roman Numerals is X (10) + V (5) + III (3) = XVIII
 

When writing a large number into Roman Numerals, we group the number.
 
To write 18 in Roman Numerals, we group 18 as 10 + 5 + 3.  

10 in Roman Numerals — X  
5 in Roman Numerals — V  
3 in Roman Numerals — III  

So, 18 is written as XVIII in Roman Numerals.
 

Roman Numerals follow a certain pattern, making it look similar. In this section, we will learn some numbers related to the Roman numeral 18.
 

• Addition rule: Addition method is used when a large number is followed by a smaller numeral; here the values are added. For example, XVIII = X + V + III = 10 + 5 + 3 = 18.  
   
• Grouping method: Here the given numbers are grouped based on their place value, and then we convert each group into its Roman numerals. For example, 18 = 10 + 5 + 3 = XVIII.  
   
• Repetition rule: Certain symbols (I, X, C, M) in the Roman numeric system can be repeated only up to three times. For example, III = 3 (I is repeated three times to represent the number 3).  
   
• Subtraction rule: Subtraction method is used when a smaller number is placed before a larger numeral. For example, IX = X - I = 10 - 1 = 9.  
   
• Roman Numeral symbols: The symbols used in the Roman numeral system are I (1), V (5), X (10), L (50), C (100), D (500), and M (1000).