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Last updated on June 26th, 2025

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Roman Numerals 1 to 20

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Roman Numerals are the symbols from the Latin letters used by Romans for daily transactions and counting purposes. In this topic, we will learn how to write Roman Numerals and their uses.

Roman Numerals 1 to 20 for UK Students
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Roman Numerals 1 to 20

Roman Numerals use symbols to represent number systems. Ancient Romans used the letters I, V, X, L, C, D, and M to represent the number system. The unavailability of zero at that time and the lack of other mathematical operations made Roman Numerals less practical in recent times. For example, we write 15 as XV.

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Roman Numbers 1 to 20 Chart

Roman numbers are used today in clocks, chapters in books, classrooms, etc. The following chart helps us to understand the numerals better.

 

List of Roman Numerals 1 to 20

 

The list of Roman Numerals provides an organized way to understand how those letters combine to represent a number. The given list starts from I (1) to XX (20). Learning these numerals helps you in a deeper understanding of the numerical system. Roman Numerals from 1 to 10 Roman Numerals from 11 to 20

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How to Write Roman Numerals 1 to 20

Roman Numerals rely on specific symbols, and it has rules of addition and subtraction. The basic symbols in Roman Numerals are:

 

I = 1

V = 5

X = 10

 

Using the above symbols, we can combine the Roman Numerals for the numbers easily. There are two basic methods of writing Roman Numerals, they are:

 

  • By Expansion Method

     
  • By Grouping Method

 

By Expansion Method:

Through the expansion method, we break down the numbers into tens and one's parts and then convert them into numerals.

 

Step 1: Break the numbers into ones and tens parts.

 

Step 2: Write Roman Numerals for each part.

 

Step 3: Combine all the parts to get the numerals.

 

Example: For the number 19.

 

Step 1: Break the numbers 10 + 9 = 19

 

Step 2: Add Roman Numerals for each part

The Roman Numeral of 10 is X.

The Roman Numeral of 9 is IX.

 

Step 3: Combine all the parts 10 (X) + 9 (IX) = XIX.

Therefore, the Roman Numeral of 19 is XIX.

 

By Grouping Method:

The grouping method directly forms the number by combining Roman Numeral symbols directly. It uses addition and subtraction rules.

 

Step 1: Start writing numerals for the largest number.

 

Step 2: Smaller numbers are either getting added or subtracted.

 

Following the rule of adding and subtraction is mandatory.

 

Addition: smaller numeral after the larger numeral.

Subtraction: smaller numeral before the large numeral.

 

Example: For the number 12.

 

Step 1: Start with the larger numbers. While splitting, we will get 10 and 2

The Roman Numeral of 10 is X

 

Step 2: Add or subtract the smaller number If we add 2 to 10 it will become 12.

The Roman Numeral of 2 is II

Therefore, the Roman Numeral of 12 is XII.

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Rules for Writing Roman Numerals 1 to 20

Roman Numerals follow rules to make sure the number is written correctly. Here are some main rules given below:

 

  • Rule 1: Addition Method

     
  • Rule 2: Repetition Method

     
  • Rule 3: Subtraction Method

     
  • Rule 4: Limitation Rule

 

Rule 1: Addition Method:

In Roman Numerals, if the smaller numeral comes after the large numeral, then we need to add their values.

Example: If the given number is XII. We can see that the number X refers to 10 and the other number refers to 2. So in this, the smaller numeral is after the large numeral, so we need to add the 10 and 2 to get the value 12.

 

Rule 2: Repetition Method:

The Roman Numeral can be repeated up to three times to increase its value. The numbers cannot be repeated after three times. Only symbols like I and X can be repeated, and V cannot be repeated.

Example: XXX = 10 + 10 + 10 = 30, repeating the numeral X for the fourth time is not allowed.

 

Rule 3: Subtraction Method:

If the smaller numeral comes before the large numeral, then we need to subtract the smaller numeral from the larger numeral to get the number. There are three rules in subtraction, they are: I can be subtracted from V and X. X can be subtracted from L and C.

Example: In the number IV. Here, V is the biggest numeral and I is the smallest numeral. As we see that the smaller numeral is before the larger numeral, we need to subtract to get the number. V (5) - I (1) = IV (4).

 

Rule 4: Limitation Rule:

Roman Numerals consist of several limitations, they are: A numeral cannot be repeated more than three times.

 

For example, III (3) cannot be repeated more than 3 times, instead, we use IV for writing 4. Subtraction cannot be done with the non-pair numbers.

 

For example, XI here X (10) - I(1) gives IX is applicable, but IC, C (100) - I(1) is not applicable. Only one subtraction can be allowed in one numeral.

 

For example, XL (40), L (50) - X (10) is applicable to get 40 but XXL is not applicable to get the number 30.

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Tips and Tricks in Number Names 1 to 20

Roman Numerals are fun to learn and easy to write when you know the following tips and tricks.

 

  • Memorize the basic symbols like I (1), V (5), and X (10), to write and read the other numerals easily.

     
  • Always break the big numerals into smaller parts to make it easier to read and write.

     
  • Remember the repetition rule, a number should not be added more than three times.

     
  • Practice the smaller numerals and gradually move to the bigger values. We use numerals in clocks, classrooms, etc., and try to read from the numeral clock to make numerals easy to learn.
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Common Mistakes and How to Avoid Them in Roman Numerals 1 to 20

It is easy to make mistakes while learning Roman Numerals, but using the following mistakes and the ways to avoid them can help you to avoid those mistakes.

Mistake 1

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Repeating numerals more than three times

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Writing numerals more than three times results in mistakes. Children will add it more than three times.

 

For example, writing IV like IIII by mistake.

Mistake 2

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Confusing addition and subtraction rule

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Kids might get confused with addition and subtraction rules. Instead of adding the number, they might end up subtracting and vice versa. Always remember that a smaller numeral before a larger numeral is subtracted, and a smaller numeral after a larger numeral is added.

 

For example, instead of writing IX (9) some children might add the smaller numeral and write it as XI (11).

Mistake 3

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Incorrect expansion of numbers

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Breaking the numerals incorrectly will lead to mistakes. Double-check the numerals with the numbers to make sure it is split correctly.

 

For example, for expanding 17 instead of writing it as 10 + 7, they may write it as 10 + 5 + 2 which gives incorrect numerals. XVII instead of XVII.

Mistake 4

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Forgetting the Value of Each Symbol

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At times, the values of the given symbols can be confusing.

 

For example, X is 10, but if X is confused as 5, then the whole answer becomes different.

Mistake 5

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Improper Order of Writing the Symbols

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We will have to write the symbols in the correct order. This will lead to wrong answers.

 

For example, when writing XVII as XVVII, like instead of writing tens in the ones place and vice versa, children make these mistakes.

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Roman Numerals 1 to 20 Examples

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Problem 1

Write the Roman Numerals for 18 using the breakdown method.

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The Roman Numeral of 18 is XVIII.

Explanation

Step 1: Break the numbers into tens and ones. 18 = 10 + 8

 

Step 2: Add numerals to each part.

The Roman Numeral of 10 is X.

The Roman Numeral of 8 is VIII.

 

Step 3: Combine the parts 10 (X) + 8 (VIII) = XVIII (18).

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Problem 2

Add X + V.

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XV

Explanation

Adding X (10) and V (5) = XV (15).

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Problem 3

Subtract XX - V.

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XV

Explanation

XX = 20

V = 5

20 - 5 = 15 = XV.

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Problem 4

Write the Roman Numeral of 20.

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XX

Explanation

The Roman Numeral of 20 is XX.

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Problem 5

Add 10 + 6 and write the answer in Roman Numeral.

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XVI.

Explanation

10 + 6 = 16

X + VI = XVI.

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FAQs on Roman Numerals 1 to 20

1.What is 10 in Roman Numerals?

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2.Write the Roman Numerals from 1 to 5.

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3.What number is V?

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4.What is the number X?

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5.Write 19 in Roman Numerals.

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6.How can children in United Kingdom use numbers in everyday life to understand Roman Numerals 1 to 20?

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7.What are some fun ways kids in United Kingdom can practice Roman Numerals 1 to 20 with numbers?

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8.What role do numbers and Roman Numerals 1 to 20 play in helping children in United Kingdom develop problem-solving skills?

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9.How can families in United Kingdom create number-rich environments to improve Roman Numerals 1 to 20 skills?

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Important Glossaries for Roman Numerals 1 to 20

  • Breaking Numbers: It is the process of splitting a larger number into smaller parts. For example, for multiplying 15, we can divide it as 10 + 5.

 

  • Repetition: Using the same symbols more than once. For example, XXX.

 

  • Numerical System: The numbers, used in ancient Rome, used Latin letters rather than digits. For example, I, II, III, etc.

 

  • Addition Method: Adding smaller numerals after larger numerals to get a sum.

 

  • Subtraction Method: Placing a smaller numeral before a larger one, indicating subtraction.
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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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