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Last updated on May 26th, 2025

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11 in Roman Numerals

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Roman numerals are the 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

11 in Roman Numerals for US Students
Professor Greenline from BrightChamps

What is 11 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 earlier. 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), D (100), and M (1000) are the symbols we use to count.

 

In Roman Numerals we use XI to represent 11, here X is 10 and I is 1.Let’s learn more about Roman numerals and how we write them.

Professor Greenline from BrightChamps

Basic Rules for 11 in Roman Numerals

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 number the smaller number is placed after the larger number, then it is the addition method. For example, XI → X + I →  10 + 1 = 11

 

Rule 2: Repetition Method

 

To write a large number, there are certain Roman Numerals that can be repeated 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 and 8 we write as VIII not IIIIIIII.
 

Professor Greenline from BrightChamps

How to Write 11 in Roman Numerals

Let’s now learn how to write 11 in Roman Numerals. Follow these methods to write the number in Roman Numerals. 

 

 

  • By Expansion Method
  • By Grouping Method
     
Professor Greenline from BrightChamps

11 in Roman Numeral by Expansion Method

In the expansion method, based on the place value, the number is broken down. In this section, we will learn how to write 11 in Roman numerals using the expansion method.

 

To write 11 in Roman Numerals, follow the steps,

 

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

For 11 we write it as 10 + 1


Step 2: Converting the number into Roman Numerals


10 in Roman Numeral — X
1 in Roman Numeral — I

 

 

Step 3: Combining them Roman Numerals together. 

 

Therefore, 11 in Roman Numeral is X (10) + I (1) = XI
 

Professor Greenline from BrightChamps

11 in Roman Numeral by Grouping Method

When writing a large number into Roman Numeral we group the number. 


To write 11 in Roman Numeral, we group 11 as 10 + 1


10 in Roman Numeral — X


1 in Roman Numeral — I


So, 11 is written as XI in Roman Numerals.
 

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Common Mistakes and How to Avoid Them in 11 Roman Numerals

Students make mistake when writing a number in Roman Numerals. To master Roman Numerals we can learn a few common mistakes and the ways to avoid them.
 

Mistake 1

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Errors in repetition method

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The repetition method can be confusing for beginners as it states that Roman Numerals cannot be repeated more than three times. In contrast, some of the Roman Numerals such as V, L, and D cannot be repeated. 
 

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11 in Roman Numerals Examples

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Max, the Girl Character from BrightChamps

Problem 1

Find the product of XI and XII.

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The product of XI and XII is CXXXII
 

Explanation

 In number XI is 11 and XII is 12. The product of XI and XII is 11 × 12 = 132. 132 in Roman Numerals can be written as CXXXII
 

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Max, the Girl Character from BrightChamps

Problem 2

A teacher wants to give CCCXXX books to XXX students. Find the number of books each student will get.

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The number of books each student will get is XI
 

Explanation

 To find the number of books a student gets we divide the number of books by the total number of students.


That is CCCXXX / XXX


CCCXXX = 330


XXX = 30


Therefore, CCCXXX / XXX = 330 / 30 = 11.


11 in Roman numerals can be written as XI.
 

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Max, the Girl Character from BrightChamps

Problem 3

Find the sum of CCXX and XI

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 The sum of CCXX and XI is CCXXXI
 

Explanation

 Sum is the result of adding two numbers.


CCXX = 220


XI = 11


220 + 11 = 231


231 in Roman Numerals is CCXXXI


 The sum of CCXX and XI is CCXXXI
 

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Max, the Girl Character from BrightChamps

Problem 4

What is the difference between XX and XI.

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The difference between XX and XI is IX. 
 

Explanation

The difference of two numbers is the value we get when subtracting the number from the other


XX = 20
XI = 11
20 - 11 = 9


9 in Roman Numerals can be written as IX.
 

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Max, the Girl Character from BrightChamps

Problem 5

Write the Roman Numeral for 11 + 47 using the expansion method.

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The Roman for 11 + 47 is LVIII
 

Explanation

Step 1: First convert the numbers 11 and 47 into Roman numerals


11 - XI
47 - XLVII

 

Add the numbers together: 11 + 47 = 58


Using expansion method: 58 = 50 + 8 = LVIII
 

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FAQs on 11 in Roman Numerals

1.What number is IX?

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2.What is XI?

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3.What is 16 in Roman Numerals?

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4.Is XI a prime number?

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5.What are the multiples of 11?

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6.How can children in United States use numbers in everyday life to understand 11 in Roman Numerals?

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7.What are some fun ways kids in United States can practice 11 in Roman Numerals with numbers?

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8.What role do numbers and 11 in Roman Numerals play in helping children in United States develop problem-solving skills?

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9.How can families in United States create number-rich environments to improve 11 in Roman Numerals skills?

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Professor Greenline from BrightChamps

Important Glossaries for 11 in Roman Numerals

  • Addition rule: Addition method is used when a large number is followed by a smaller numeral, here the values are added. For example, XI = X + I = 10 + 1 = 11 

 

  • Grouping method: Here the given numbers is grouped based on their place value and then we convert each group into its Roman numerals. For example, 11 = 10 + 1 = XI

 

  • 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).
     
Professor Greenline from BrightChamps

About BrightChamps in United States

At BrightChamps, we understand numbers are more than symbols—they unlock endless possibilities! Our goal is to guide children across the United States in mastering essential math skills, focusing today on the 11 in Roman Numerals with special attention to Roman numerals—in a fun, engaging, and easy-to-understand way. Whether your child is calculating how quickly a roller coaster zips through Disney World, tracking scores at Little League baseball games, or budgeting their allowance for cool gadgets, having solid number skills builds their confidence for daily tasks. Our interactive lessons make learning enjoyable and straightforward. Since kids across the USA have unique learning styles, we customize our methods to match each child. From the vibrant streets of New York City to the sunny beaches of California, BrightChamps makes math come alive, relatable, and exciting throughout America. Let’s bring Roman numerals to life on every child’s math path!
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Hiralee Lalitkumar Makwana

About the Author

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.

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Max, the Girl Character from BrightChamps

Fun Fact

: She loves to read number jokes and games.

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