Roman Numerals: 121 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 Roman numerals. Earlier, people used fingers, sticks, bones, etc., to count. When life became 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 CXXI to represent 121, where C is 100, X is 10, and I is 1. 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, CXXI → C + X + X + I → 100 + 10 + 10 + 1 = 121

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 is followed by a large number in Roman numerals, we subtract the smaller number from the large number. 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, and for 8, we write VIII, not IIIIIIII.
 

Let’s now learn how to write 121 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 121 in Roman numerals using the expansion method.

To write 121 in Roman numerals, follow these steps:

Step 1: Break the number based on place value. Place values are ones, tens, hundreds, etc.

For 121, we write it as 100 + 20 + 1.

Step 2: Convert the number into Roman numerals:

100 in Roman numerals — C
20 in Roman numerals — XX
1 in Roman numerals — I

Step 3: Combine the Roman numerals together.

Therefore, 121 in Roman numerals is C (100) + XX (20) + I (1) = CXXI.
 

When writing a large number into Roman numerals, we group the number. To write 121 in Roman numerals, we group 121 as 100 + 20 + 1:

100 in Roman numerals — C

20 in Roman numerals — XX

1 in Roman numerals — I

So, 121 is written as CXXI in Roman numerals.
 

Roman numerals follow a certain pattern, making them look similar. In this section, we will learn some numbers related to the Roman numeral 121:

• Addition Rule: The addition method is used when a large number is followed by a smaller numeral; here, the values are added. For example, CXXI = C + XX + I = 100 + 20 + 1 = 121.
   
• Grouping Method: Here, the given numbers are grouped based on their place value and then converted into Roman numerals. For example, 121 = 100 + 20 + 1 = CXXI.
   
• Repetition Rule: Certain symbols (I, X, C, M) in the Roman numeral system can be repeated only up to three times. For example, XXX = 30 (X is repeated three times to represent the number 30).
   
• Subtraction Rule: The subtraction method is used when a smaller numeral precedes a larger numeral, indicating subtraction. For example, IV = 4 (5 - 1).
   
• Roman Symbols: The fundamental symbols in Roman numerals are I (1), V (5), X (10), L (50), C (100), D (500), and M (1000).