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Last updated on May 26th, 2025

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C in Roman Numerals

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To meet their daily commerce and administration needs, the ancient Romans developed Roman Numerals. It used a combination of seven symbols — I, V, X, L, C, D, and M to represent numbers. Roman numerals were used to record transactions, keep track of data, and label military units. In this topic, we are going to learn about the Roman numeral C.

C in Roman Numerals for US Students
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What is C in Roman Numerals?

Ancient Romans discovered that counting fingers could get very complicated after 10. So to overcome the complexity, the Roman numeric system was developed. This was widely used throughout Europe as a standard writing system until the late Middle Ages. Seven symbols are used to represent numbers in the Roman numeric system — I, V, X, L, C, D, and M. The numerals are made up of different combinations of these symbols. C in Roman numerals can be written in number form as 100.

 

Let us learn more about the Roman numeral C, how we write it, the mistakes we usually make, and ways to avoid these mistakes.

c roman numerals

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Basic Rules for C in Roman Numerals

When writing Roman numerals, there are a few rules that we need to follow based on the Roman numerals we are trying to write. In this section, we will learn about the rules when writing Roman numerals and how to represent them.

 

Rule 1: Addition Method:

When a larger symbol is followed by a smaller symbol, we add the numerals to each other. For example, in VIII, we have 5 + 3 = 8

 

Rule 2: Repetition Method:

A symbol that is repeated three times in continuation increases the value of the numeral. For example, XXX = 30

 

Rule 3: Subtraction Method:

We use the subtraction method when a larger symbol follows a smaller symbol. For example, XL = 40 (which is 50 – 10).

 

Rule 4: Limitation Rule:

Symbols cannot be repeated more than three times, and some symbols, such as V, L, and D cannot be repeated more than once. For example, 10 is represented as X and not VV.

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How to Write C in Roman Numerals?

Let us learn about how to write C in Roman numerals. There are two methods that we can use to write Roman numerals:

 

  • By Expansion Method
  • By Grouping Method
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C in Roman Numeral by Expansion Method

The breaking down of Roman numerals into parts and then converting them into numerals is what we call the expansion method. The expansion method is the breaking down of Roman numerals into numerical form and adding them to get the final number.

 

Step 1: Break the Roman numerals into parts.

Step 2: Now write each of the Roman numerals with its numerical digit in the place value.

Step 3: Add the numerals together.

 

For C,

Step 1: The Roman numeral C stands alone. C = 100

Step 2: Write the Roman Numerals for each part The Roman Numeral C is 100

Step 3: Combine all the numbers As there is only one part, C = 100. Therefore, the Roman Numeral C is 100.

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C in Roman Numeral by Grouping Method

Using subtraction and addition rules, we will apply the grouping method. This means we break the Roman numerals into smaller groups, which makes it easier to work with. This method groups the Roman numerals logically, and then we write the numbers for each group.

 

Step 1: Take the largest number and write the number for that Roman numeral.

Step 2: Write the Roman numeral using the subtraction and addition rules

 

Example: Let’s take the Roman numeral C.

Step 1: The larger Roman numeral is what we will begin with. The numeral for C is 100

Step 2: As C is a single numeral, no additional grouping or subtraction is needed. Therefore, the numeral for C is 100.

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Common Mistakes and How to Avoid Them in C Roman Numerals

Students can make mistakes when studying Roman numerals. Here are a few common mistakes students make, and ways to avoid them.

Mistake 1

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Mistakes when applying the repetition method

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It can be quite confusing for beginners to remember that Roman Numerals cannot be repeated more than three times. Another thing to keep in mind is that Roman Numerals such as V, L, and D cannot be repeated.

 

For example, writing LL as 100 is incorrect; the correct answer is C.

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c Roman Numerals Examples

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Problem 1

Combine the historical dates MCMXCVIII and MDCCCXCVI. Write the total in Roman numerals.

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The sum is MMMDCCCXCIV

Explanation

Convert both Roman numerals into their decimal form:

MCMXCVIII = 1998

MDCCCXCVI = 1896

Now add both numbers: 1998 + 1896 = 3894

Now convert the number into its Roman numeral: 3894 = 3000 (MMM) + 800 (DCCC) + 90 (XC) + 4 (IV) = MMMDCCCXCIV

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Problem 2

What is the remaining amount when MMXXI is subtracted from MMXXIII? Express in Roman numerals.

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The difference is II

Explanation

Convert the Roman numerals into their decimal form:

MMXXIII = 2023

MMXXI = 2021

Now subtract the numbers: 2023 - 2021 = 2

Convert the number into its Roman numeral: 2 = II

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Problem 3

Halve the Roman numeral C. What is the result in Roman numerals?

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L

Explanation

Convert C into its decimal form:

C = 100

Divide by 2: 100/2 = 50

Write 50 in Roman numerals: 50 = L

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Problem 4

Calculate the product of C and XIII. Present the result in Roman numerals.

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The product is MCCC

Explanation

Write C and XIII in numbers:

C = 100

XIII = 13

Multiply the numbers: 100 × 13 = 1300

Convert 1300 into its Roman numerals: 1000 (M) + 300 (CCC) = MCCC

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Problem 5

Convert the Roman numeral CCXLVII into its decimal form.

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In decimal form, CCXLVII is 247

Explanation

Break CCXLVII into components:

CC = 200 (C + C)

XL = 40 (50 - 10)

VII = 7 (V + I + I)

Add values: 200 + 40 + 7 = 247

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FAQs on C in Roman Numerals

1.What is L in Roman numerals?

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2.Is C a prime number?

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3.What is C + C?

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4.What is CL?

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5.Subtract X from C

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

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

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8.What role do numbers and C 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 C in Roman Numerals skills?

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Important Glossaries for C in Roman Numerals

  • Limitation Rule: There are some symbols that cannot be repeated more than once (V, L, D). For example, VV for 10 is wrong; the correct answer is X.

 

  • Place value: The position of a digit in a number, this position determines its value. For example, the number 2 in 20 is in the ten's place.

 

  • Subtraction Method: A method where a smaller numeral before a larger numeral is subtracted from the larger numeral. For example, IX is 9 (10 - 1).

 

  • Addition Method: A method where numerals are added together when a smaller numeral follows a larger numeral. For example, VI is 6 (5 + 1).

 

  • Repetition Method: A method where repeating a numeral up to three times increases its value. For example, XXX is 30.
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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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