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Roman numerals represent a number system that uses letters to express numbers collectively. The ancient Romans used the letters I, V, X, L, C, D, and M to write numbers. The Roman letters were used for the purpose of counting and performing other day-to-day transactions. The Roman letters are utilized as general suffixes for people across generations, as hour marks on a clock, to denote the names of Popes and Monarchs, etc. Let us learn how to write and interpret Roman numerals and also explore the rules for Roman numbers.
|1.||What are Roman Numerals?|
|2.||Roman Numerals Chart|
|3.||Rules for Roman Numerals|
|4.||Tips to Remember Roman Numerals|
|5.||FAQs on Roman Numerals|
What are Roman Numerals?
Roman numerals represent a number system that was widely used throughout Europe as the standard writing system until the late middle ages. The ancient Romans explained that when a number reaches 10 it is not easy to count on one’s fingers. Therefore, there was a need to create a proper number system that could be used for trade and communications.
Modern Roman numerals use 7 letters to represent different numbers. These are I, V, X, L, C, D, and M which represent the numbers 1, 5, 10, 50, 100, 500, and 1000 respectively.
Roman Numerals Chart
The Roman numerals chart can prove to be very helpful when converting a Roman numeral to an integer value or vice versa. The following Roman numerals list shows how the numbers are expressed in Roman numerals.
As mentioned above there are seven Latin letters that are used to represent Roman numerals. By changing the placement of these letters we can convert a natural number into a Roman numeral. Similarly, the converse operation can also be performed.
For example, we have the Roman numeral LX. The value is (50 + 10) = 60. Thus, we can say that if a symbol holding a greater value is placed after another symbol of greater or equal value, it is added. However, if a symbol of a smaller value is placed before a greater value symbol, it is subtracted. Thus, XL will be (50 - 10) = 40.
In addition to these basic conversions, there are a couple of rules that need to be remembered while converting Hindu-Arabic numbers to Roman numerals and vice versa. You can use the Roman Numerals Calculator to verify your answers.
Rules of Roman Numerals
It is necessary for us to remember the rules for reading and writing Roman numbers in order to avoid mistakes. Here is a list of the basic rules for Roman numerals.
- Rule 1: When certain numerals are repeated, the number represented by them is their sum. For example, II = 1 + 1 = 2, or XX = 10 + 10 = 20, or, XXX = 10 + 10 + 10 = 30.
- Rule 2: It is to be noted that no Roman numerals can come together more than 3 times. For example, we cannot write 40 as XXXX
- Rule 3: The letters V, L, and D are not repeated.
- Rule 4: Only I, X, and C can be used as subtractive numerals. There can be 6 combinations when we subtract. These are IV = 5 - 1 = 4; IX = 10 - 1 = 9; XL = 50 - 10 = 40; XC = 100 - 10 = 90; CD = 500 - 100 = 400; and CM = 1000 - 100 = 900
- Rule 5: When a Roman numeral is placed after another Roman numeral of greater value, the result is the sum of the numerals. For example, VIII = 5 + 1 + 1 + 1 = 8, or, XV = 10 + 5 = 15,
- Rule 6: When a Roman numeral is placed before another Roman numeral of greater value, the result is the difference between the numerals. For example, IV = 5 - 1 = 4, or, XL = 50 - 10 = 40, or XC = 100 - 10 = 90
- Rule 7: When a Roman numeral of a smaller value is placed between two numerals of greater value, it is subtracted from the numeral on its right. For example, XIV = 10 + (5 - 1) = 14, or, XIX = 10 + (10 - 1) = 19
- Rule 8: To multiply a number by a factor of 1000 a bar is placed over it.
- Rule 9: Roman numerals do not follow any place value system.
- Rule 10: There is no Roman numeral for zero (0).
Now, let us use these rules to read Roman numerals.
How to Read Roman Numerals?
Roman numerals can be read easily if we remember the rules given above. However, a simple way to write the Roman numerals in Hindu-Arabic numbers is to expand the given Roman number and then add all of them together. For example, if we have XVII, we can expand and add them as, X + V + I + I = 10 + 5 + 1 + 1 = 17.
Let us read and write Roman numerals with the help of a few examples.
Example 1: What is LVI in Roman numerals?
Solution: Using the rules and the Roman numerals chart given above, we know that L = 50, V = 5, and I = 1. So we will expand and add the values of all the letters. This will be L + V + I = 50 + 5 + 1 = 56.
Example 2: What does XXVI mean in numbers?
Solution: We know that X = 10 and V = 5, and I = 1. So, let us expand the values and then add them as X + X + V + I = 10 + 10 + 5 + 1 = 26.
Example 3: Find the value of MCMXI - CLX
Solution: We know the values of M = 1000, C = 100, X = 10, L = 50 and I = 1.
Now, here, we need to observe that in MCMXI, the letter C has an M after it. So, we need to remember the rule for Roman numerals which says that, when a Roman numeral is placed before another Roman numeral of greater value, the result is the difference between the numerals. If we observe the given Roman numeral, MCMXI, we can see that C is placed before M which is of greater value, so we will subtract them, (M - C) and then the expansion will be as M + (M - C) + X + I = 1000 + (1000 - 100) + 10 + 1 = 1000 + 900 + 10 + 1 = 1911. This means Roman Numeral MCMXI is equal to 1911 and the value of CLX = C + L + X = 100 + 50 + 10 is 160.
Now, MCMXI - CLX = 1911 - 160 = 1751
1751 in Roman Numerals = 1000 + 700 + 50 + 1 = MDCCLI
Years in Roman Numerals
Here is a list of pages that explain how to write a few years in Roman numerals.
- 2022 in Roman Numerals
- 2021 in Roman Numerals
- 2020 in Roman Numerals
- 2019 in Roman Numerals
- 2018 in Roman Numerals
Roman Numerals Worksheet
Roman numerals worksheets can promote a better understanding of reading and writing Roman numerals. It consists of problems like converting numbers to Roman numerals and vice versa, word problems, etc. The following list shows a few pages of Roman numerals worksheets with downloadable pdfs.
Roman Numerals Worksheet - 1
Roman Numerals Worksheet - 2
Roman Numerals Worksheet - 3
Roman Numerals Worksheet - 4
Tips to Remember Roman Numerals
The following tips are helpful in learning the rules of Roman numerals.
- Using Mnemonics: Mnemonics are memory devices that help us retain and memorize things using simple tricks. The mnemonic that we use here is My Dear Cat Loves Xtra Vitamins Intensely. Here, the first letters in bold show the Roman numerals in descending order.
- Practice Problems: Practicing questions on the topic of Roman numerals is always the best way to remember the rules of Roman numerals.
Numbers to Roman Numerals
To convert Hindu-Arabic numbers to Roman Numerals, we split the numbers into their least expandable form, write their respective Roman letter and add or subtract them. For example, 2021 in Roman numerals: 2021 = 1000 + 1000 + 10 + 10 + 1 = MMXXI
Roman Numerals to Numbers
To convert Roman numerals to numbers, we split the Roman numerals into single letters, write their numerical values and add or subtract them, i.e., XII = X + I + I = 10 + 1 + 1 = 12. Here is a list of pages that express the Hindu-Arabic form of a few Roman numerals.
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Roman Numerals Examples
Example 1: Henry wants to know if it is time for his favorite show. The shorthand of the clock points at the Roman numeral VIII. What hour is it?
We know that V stands for 5 and I stands for 1. Since I is the smaller symbol and appears thrice after V, it will get added to V.
VIII = V + I + I + I, Thus, the time is 8 o'clock.
Example 2: Willow was asked to represent a Roman numeral using both addition and subtraction. If the Roman numeral is XIX, how will she represent it in a decimal number system?
In this question, we need to remember the rule for Roman numerals which says that, when a Roman numeral is placed before another Roman numeral of greater value, the result is the difference between the numerals. If we observe the given Roman numeral, XIX, we can see that I is placed before X which is of greater value, so we will subtract them. This will be written as, X + (X - I) = 10 + (10 - 1) = 10 + 9 = 19
∴ XIX = 19
Example 3: How to write the year 2019 in Roman numerals?
The biggest symbol in 2019 is 1000, which is M. We will break down the number further. 2019 becomes 1000 + 1000 + 10 + 9
∴ 2019 = MMXIX
FAQs on Roman Numerals
What are Roman Numerals in Maths?
Roman numerals are those Roman letters that do not follow a place value system. They have Latin alphabets I, V, X, L, C, D, and M that represent the numbers 1, 5, 10, 50, 100, 500, and 1000 respectively. Every number can be expressed as a Roman numeral using certain rules that are defined by the Roman numbers.
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What are the Basic Rules to Write Roman Numerals?
Here is a list of the basic rules to write Roman numerals.
- A letter can be repeated only thrice in succession.
- A large number written to the left of a smaller number leads to the addition of both values.
- A large number written to the right of a smaller number leads to the subtraction of a lesser value from the greater number.
- Only I, C, and X can be used as numerals used for subtraction.
How to Write 2020 in Roman Numerals?
The number 2020 first needs to be broken down into its component values. Accordingly, 2020 can be expressed as, 2020 = 1000 + 1000 + 10 + 10 = M + M + X + X = MMXX. Hence, 2020 can be written as MMXX in Roman numerals.
What is Roman Numeral XXVII in Numbers?
We first denote each Roman numeral as its corresponding integer value. XXVII can be expressed as X + X + V + I + I = 10 + 10 + 5 + 1 +1 = 27. Thus, XXVII in Roman numerals is 27.
How to Write Roman Numbers?
Roman numbers are written using 7 Roman letters that represent the following numbers. Using these letters, we can form any number with the help of certain rules.
- 1 is represented by I.
- 5 is represented by V.
- 10 is represented by X.
- 50 is represented by L.
- 100 is represented by C.
- 500 is represented by D.
- 1000 is represented by M.
Using these combinations, numbers can be easily converted to Roman numerals symbols.
What is the Roman Numeral M in Numbers?
There are 7 primary numbers that are available in the Roman numeral system and the highest is represented by M. The Roman numeral M represents 1000 or thousand from the decimal number system.
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What is the Roman Numeral for 6?
The value for Roman number 6 can be found in the following manner. 6 = 5 + 1. As per the list of the Roman numerals, we know that 5 is V and 1 is I. And that makes the Roman numeral conversion of 6 as VI.
What is the Roman numeral for 5000?
The Roman numeral M stands for 1000. As M cannot be repeated more than 3 times, and for larger numbers, we denote bar over the basic Roman Numeral, 5000 is written as V̅ in Roman numerals.
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How to Write 100 in Roman Numerals?
The letter C is used to represent 100 in the Roman numeral system. The number 100 is represented by the letter C in Roman numerals.
What is Zero in Roman Numbers?
According to the Roman numerals history, the Roman system did not have any letter that would represent zero. Zero was defined as nulla. In Latin, the word nulla means none. So far there is no specific letter to represent zero in the Roman numeral system.
How do I Teach My Child Roman Numerals?
The first step is to introduce the Roman numeral system in terms of natural numbers. Children need to build a foundation of the 7 fundamental numbers and what letters are used to represent them. Finally, you need to teach kids the steps to convert a natural number to a Roman numeral and vice versa.
Where are Roman Numerals used in Everyday Life?
Roman numerals are used in the French Republican Calendar. They are also used to denote the varying levels of brightness in photography, the magnitude of earthquakes in seismology, hierarchical relationships, page numbering of books, chapter numbers, and so on.
How to Do Counting in Roman Numbers?
Counting in Roman numerals is represented with the help of seven special letters to represent different numeric values. These special letters are I, V, X, L, C, D, and M. These letters individually hold a numeric value. Such as the numeric value of I is 1, V is 5, X is 10, L is 50, C is 100, D is 500, and M is 1000 respectively. Counting in the Roman numerals is represented as One (I), two (II), three (III), four (IV), five (V), and so on.
How to Convert Roman Numerals to Numbers?
Roman numerals can be easily converted into numbers if we remember the basic rules of Roman numerals. However, a simple way to write the Roman numerals in Hindu-Arabic numbers is to expand the given Roman number and then add all of them together. For example, if we have XVII, we can expand and add them as, X + V + I + I = 10 + 5 + 1 + 1 = 27. We also need to remember the rules given below.
- When certain numerals are repeated, the number represented by them is their sum. For example, II = 1 + 1 = 2, or XX = 10 + 10 = 20, or, XXX = 10 + 10 + 10 = 30.
- It is to be noted that no Roman numerals can come together more than 3 times. For example, we cannot write 40 as XXXX
- The letters V, L, and D are not repeated.
- Only I, X, and C can be used as subtractive numerals. There can be 6 combinations when we subtract. These are IV = 5 - 1 = 4; IX = 10 - 1 = 9; XL = 50 - 10 = 40; XC = 100 - 10 = 90; CD = 500 - 100 = 400; and CM = 1000 - 100 = 900
- When a Roman numeral is placed after another Roman numeral of greater value, the result is the sum of the numerals. For example, VIII = 5 + 1 + 1 + 1 = 8, or, XV = 10 + 5 = 15
- When a Roman numeral is placed before another Roman numeral of greater value, the result is the difference between the numerals. For example, IV = 5 - 1 = 4, or, XL = 50 - 10 = 40, or XC = 100 - 10 = 90
- When a Roman numeral of a smaller value is placed between two numerals of greater value, it is subtracted from the numeral on its right. For example, XIV = 10 + (5 - 1) = 14, or, XIX = 10 + (10 - 1) = 19
How to Write a Date in Roman Numerals?
In order to write a date in Roman numerals, we use the following procedure. Let us convert the date 14 - 10 - 2021 to Roman numerals. So, 14 will be XIV, 10 will be X, and 2021 will be MMXI. Now, this will be together written as XIV - X - MMXI.
What is C in Roman Numerals?
In Roman numerals, C is used for the number 100. This letter C can be used to write 900 when we know that M = 1000 and we can place C before M which gives us CM = 1000 - 100 = 900. C is also used to express 90 as in XC because XC = 100 - 10 = 90, or, CD = 500 - 100 = 400.
How to Read Roman Numerals?
Roman numerals can be easily read by expanding them. Then, we substitute the respective values and add or subtract them accordingly. For example, let us read the Roman numeral, VII. After expanding this, we get, V + I + I. After substituting the values as V = 5, I = 1, we get 5 + 1 + 1 = 7.
How many Roman Letters are there?
The numerical system of Roman letters consists of 7 Latin letters. They are I, V, X, L, C, D, and M. Here I represents 1, V represents 5, X represents 10, L represents 50, C represents 100, D represents 500, and M represents 1000.
How to Write 40 in Roman Counting?
In Roman numerals, 40 is written as XL. We know that L represents 50 and X represents 10. Since we have the letter L for 50, and we need 10 less than 50 to get 40, we write X before L and hence we get XL.