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Last updated on February 27th, 2025

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I Roman Numerals

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Foundation
Intermediate
Advance Topics

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 I.

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What is I 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. The Roman numeral I represents the number 1.

 

Let us learn more about the Roman numeral I, how we write it, the mistakes we usually make, and ways to avoid these mistakesi roman numerals

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Basic Rules for I 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 VI, we have 5 + 1 = 6.

 

Rule 2: Repetition Method:

A symbol that is repeated increases the value of the numeral. For example, III = 3.

 

Rule 3: Subtraction Method:

We use the subtraction method when a larger symbol follows a smaller symbol. For example, IV = 4 (which is 5 – 1).

 

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 I in Roman Numerals?

Let us learn about how to write I 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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I 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 numeral 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 I,

Step 1: First, we break the Roman numeral. I = I

 

Step 2: Write the Roman Numerals for each part The Roman Numeral I is 1

 

Step 3: Combine all the numbers I = 1. Therefore, the Roman Numeral I is 1.

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I 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 I.

 

Step 1: The larger Roman numeral is what we will begin with. Once split, the Roman numeral we get is I. The numeral for I is 1.

 

Step 2: No addition or subtraction is needed. Therefore, the numeral of I is 1.

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Common Mistakes and How to Avoid Them in I Roman Numerals

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i Roman Numerals Examples

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Problem 1

Find the sum of XIX + XXII. Write the answer in Roman numerals.

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Explanation

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Problem 2

What is the difference between L - XXVII? Write in Roman numerals.

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Explanation

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Problem 3

Divide XL by 2 and write the answer in Roman numerals.

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Explanation

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Problem 4

Find the product of XI and IV.

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Explanation

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Problem 5

Convert XXI into its decimal form.

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Explanation

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FAQs on I in Roman Numerals

1.What is II in Roman numerals?

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2.Is I a prime number?

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3.What is I + I?

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4.What is III?

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5.Subtract I from V

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Important Glossaries for I 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 1 in 10 is in the ten's place.
     
  • Prime Number: A number greater than 1 that has no positive divisors other than 1 and itself. For example, 2 is a prime number.
     
  • Grouping Method: Breaking down Roman numerals into smaller groups to make calculations easier.
     
  • Subtraction Method: A method used in Roman numerals where a smaller numeral placed before a larger numeral indicates subtraction. For example, IV is 4.
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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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: She loves to read number jokes and games.

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