XLII In Roman Numerals | How To Write XLII Roman Numerals?

The Roman numerals XLII represent the number 42. But, do you find it difficult to convert Roman numerals to Arabic numbers or vice versa? If that is the case,  no worries! You have come to the right place as this article is specially designed to guide you on all you need to know about XLII Roman Numerals and how you can easily convert Roman numerals of any sort to Arabic numbers. Stay tuned!

Roman numerals are important in our daily activities because it is an integral part of elementary syllables in schools, it is also used in ranking, and above all, most of the clocks or wristwatches in use today are calibrated using Roman numerals.

Meanwhile, Roman numerals are important in both elementary and high schools because it is an essential foundation for understanding the concept of mathematics. Hence, we have carefully penned down all the rules you need to follow when converting from Roman numerals to Arabic numbers and lots more. Keep scrolling through the article to get the right guide that you desire.

What Are Roman Numerals?


Roman numerals as the name implies can be traced back to the Ancient Roman Empire. The Roman numerals numbering system has been used by most Europeans for over 1800 years. This simply means that the Roman numbering system is older than the present Hindu-Arabic system of numbering which is predominantly used today. 

Primarily, the Roman numerals numbering system is based on addition though sometimes it may also use the principle of subtraction. In most cases, the numerals can be added together to represent a large number. Whichever way, Roman numerals have come to stay and we will continue to use them in our daily activities.

XLII Roman Numerals


As I have noted in the introduction, XLII Roman numerals represent 42. 

But in this section, we are going to look at how to convert Roman numerals to Arabic numbers and vice versa. 

For easy comprehension, I have decided to summarize the conversion process in the table below. All you have to do is to pay keen attention and I bet you that you will get the gist easily. Let’s go

Thousands Hundreds Tens  Ones
Arabic Numerals 4 2
1 M C X I
5 D L V


From the table above, we can see that 4 is under the Tens column and 2 is under the One’s column. From the table now, we see that the fourth row has Roman numerals of XL while the second row on the one’s column contains II. Hence when you add the two together i.e XL + II you will get XLII which is equal to 42 in an Arabic form.

Meanwhile, if you want to convert from Arabic to Roman numerals or vice versa. Simply put the number as in the above table, and definitely, the number will appear in the exact form that you want it to be. However, due to the limitations of the Roman numbering system, it is only possible to convert numbers from 1 to 3999.

However, to be able to convert Roman and Arabic numerals using the table above, you have to handle one Arabic digit at a time and then translate it to the right Roman number. But when using the table, it is pertinent for you to note that both the column and row for zeroes are usually empty, so ensure that your table is properly fixed before you start the conversion to avoid making mistakes.

Once you draw your table properly as the one above and tackle one Arabic digit at a time, I assure you that you will get the right answer when you carry out any other conversion.

Rules For Converting Roman Numerals


All the known Roman numerals consist of a set of seven symbols. These combinations follow four vital principles. Hence, you must Know and adhere to these four key rules when converting Roman numerals.

Hence, this section is designed to guide you on what the rules are all about, and how it works with their application attached to enable you to use them without making mistakes. 

  • First Rule

This rule states that when a smaller symbol is after a great symbol, it is added.

The examples can be seen below;

  1. XVIII = 10 + 5 + 3 = 18
  2. LV = 50 + 5 = 55
  • Second Rule

This rule says that when a smaller symbol appears before a greater symbol, it should be subtracted

Some of the examples are outlined below

  1. IX = 10 – 1 = 9
  2. XXL= 50 – 10 – 10 = 30
  3. CCM = 1000 – 100 – 100 = 800
  • Third Rule

This rule states that the same symbol cannot be repeated more than three times in a row.

The examples can be seen below

  1. XXX = 10 + 10 + 10 = 30, hence 40 is not XXXX instead it is XL.
  1.  CCC = 100 + 100 + 100 = 300, but 400 is not CCCC. Instead, 400 is a CD, etc.
  • Fourth Rule

This states that if a symbol comes after itself, it is added.

The examples are below

  1. CCC = 100 + 100 + 100 = 300
  2. CCLV = 100 + 100 + 50 + 5 = 255

Now that you have understood the rules, let’s quickly convert XLII to numbers.

First of all, look carefully at this Roman numeral


The next thing is to find the value of each symbol in the Arabic numerals and then subtract or add the values to convert them to digits.

Let’s quickly start by determining the value of each symbol

X – 10

L – 50

II – 2

But 42 = (50-10) + 2

Now replace the values above with roman numerals which will give you

42 = (L – X) + II

Therefore, 42 = XLII. And that’s all, as simple as that. 

Facts About Number 42


This number (42) which is an even number is divisible by 2, 3, 6, 7, 14, and 21 and also it can be prime factorized into 2×3×7.

42 in binary form is: 101010

42 as an octal number: 52

42 is also a hexadecimal number i.e  2A

And finally, the chemical element with atomic number 42 is Molybdenum (Mo).

Numbers That Are Close To XLII


Few numbers are close to XLII(42) which ranges from IX (39) to XLV(45)

The table below summarizes it with the columns on the right indicating how each Roman numeral adds up to get the total.

S/N Number Roman Numerals Arithmetic Involved
1. 39 XXXIX 10 + 10 + 10 + 10 – 1
2. 40 XL 50 – 10
3. 41 XLI 50 – 10 + 1
4. 42 XLII 50 – 10 + 1 + 1
5. 43 XLIII 50 – 10 + 1 + 1 + 1
6. 44 XLIV 50 – 10 + 5 – 1
7. 45 XLV 50 – 10 + 5


The Major Roman Symbols Used To Represent Arabic Numbers 


There are seven major symbols in the Roman numerals which form the basis of conversion. It is either you are adding or subtracting numbers from these seven basic symbols.

The table below summarizes the symbols with the values attached

S/N Symbol Value
1. I 1
2. V 5
3. X 10
4. L 50
5. C 100
6. D 500
7. M 1000


What Is The Numeral For 42?


The Roman numeral for 42 is XLII.

To convert 42 to Roman numerals, you have to write 42 in expanded form, which is 42 = (50 – 10) + 1 + 1.

After that, replace each number with the corresponding numerals and it will look like this 42 = (L – X) + I + I = XLII.

What Does XLII Mean?


XLII means 42.

It is a Roman numeral that represents forty-two(42)



In this article on XLII Roman Numerals, We discuss exhaustively what Roman numerals are, and how they can be converted to Arabic numbers. I hope that if you follow this article succinctly, you will perform any form of conversion from Roman numerals to Arabic numbers or vice versa.

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