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Last updated on May 26th, 2025

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109 in Roman Numeral

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The ancient way of writing numbers in roman numerals. Today, we still see numerals in clocks and movie sequels. Here, we focus on the Roman numeral of 109.

109 in Roman Numeral for Filipino Students
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What is 109 in Roman Numerals

Roman numerals use alphabets to represent each number. The roman numeral 109 is CIX, where C is 100 and IX is 9.
 

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Basic rules for CIX in Roman Numeral

  • Addition Method

The values get added when the smaller number follows the larger number.
Example:  LX (60) + III (3) = LXIII (63)
Therefore, 109 in roman numeral is expressed as C (100) + VIX (9) = CIX (109)

 

  • Repetition Method

The repetition method won’t allow the letter to be repeated more than three times.  For example, we can write the roman numeral I repeatedly for 10 times to denote the number 10. For 109, we write a CIX. Where C means 100 and IX is 9

 

  • Subtraction Method

The smaller value is subtracted from the larger number. Example:  5-1 = V - I = IV (4). The number ‘1’ comes after ‘5’ so that I is subtracted from V to get IV (4).

 

  • Limitation Rule

The roman numerals cannot be repeated more than three times. For example, instead of writing ‘IIIIIII’, we write VIII for 8, where V is 5 and III is 3.
 

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How to write CIX in Roman Numeral

There are two methods to write the number in ancient form, roman numerals. The methods are:

 

109 in Roman Numeral by Expansion Method


Here, we break the number into its corresponding place value.

Step 1: We break 109 as 1 in the hundreds place, 0 in the tens place, and 9 in one's place.
Step 2: The numbers in the place value will get converted into roman numerals
Step 3: Join the roman numerals to get the desired number


So, 109 in roman numerals is CIX. Where C is 100 and IX is 9.

 

CIX in Roman Numerals by Grouping Method


The larger roman numeral gets broken into smaller parts.


For CIX,


C → 100
IX → 9


Add (100 + 9)→109
 

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Common Mistakes and How to Avoid Them in CIX

Making mistakes while writing a number in roman numerals is normal. Here are some mistakes that can happen and the solutions to tackle them.
 

Mistake 1

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Writing too many I’s
 

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‘I’ can be repeated up to three times. If it is repeated more than three times, it's incorrect. For example, IIIIIIIII is incorrect.
 

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109 in Roman Numerals Examples

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Problem 1

Simplify (CIX + IX) in roman numerals

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CXVIII
 

Explanation

CIX + IX is 118. Therefore, 118 in roman numeral is CXVIII, where C is 100, X is 10, and VIII is 8
 

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Problem 2

Find M- CIX

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DCCCXCI
 

Explanation

M and CIX represent 1000 and 109. Subtracting 109 from 1000 will give 891, which is DCCCXCI in roman numerals. Where D is 500 and CCC is 800 XCI is 91.
 

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Problem 3

Verify if CIX - IX is C

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Yes, CIX - IX is C (100)
 

Explanation

CIX - IX  = 109 - 9 = C (100)
 

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FAQs on 109 in Roman Numerals

1.Is 109 even?

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2.What is D in roman numerals?

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3.Is 109 a prime?

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4.Write 666 in roman numerals and in words

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5.What does the Roman numeral CXXXV mean?

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6.How can children in Philippines use numbers in everyday life to understand 109 in Roman Numeral?

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7.What are some fun ways kids in Philippines can practice 109 in Roman Numeral with numbers?

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8.What role do numbers and 109 in Roman Numeral play in helping children in Philippines develop problem-solving skills?

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9.How can families in Philippines create number-rich environments to improve 109 in Roman Numeral skills?

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Professor Greenline from BrightChamps

Important Glossaries for CIX in Roman Numeral

  • Roman Numeral: Letter that denotes a number. For example, M denotes 1000

 

  • Grouping Method: Splitting of larger number into smaller sections

 

  • Subtraction Method: Subtracting a letter with low value from a letter with greater value. For example, subtracting X (10) from L (50) to get XL (40)
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About BrightChamps in Philippines

At BrightChamps, numbers are more than just digits—they are keys to limitless possibilities! Our goal is to help children throughout the Philippines develop crucial math skills, focusing today on the 109 in Roman Numeral with a special focus on Roman numerals—in a lively, fun, and easy-to-follow way. Whether your child is calculating the speed of a roller coaster at Enchanted Kingdom, keeping track of scores at a basketball game, or managing their allowance to buy the newest gadgets, mastering numbers builds confidence for daily life. Our interactive lessons make learning fun and easy. Since kids in the Philippines learn in diverse ways, we tailor our approach to fit each child’s unique style. From the bustling streets of Manila to the beautiful islands of Palawan, BrightChamps brings math to life, making it relatable and exciting throughout the Philippines. Let’s make Roman numerals a fun part of every child’s learning journey!
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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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Fun Fact

: She loves to read number jokes and games.

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