21 in Roman Numerals
21 in Roman numerals is XXI. To convert 21 in Roman Numerals, we will write 21 in the expanded form, i.e. 21 = 10 + 10 + 1 thereafter replacing the transformed numbers with their respective roman numerals, we get 21 = X + X + I = XXI. In this article, we will explain how to correctly transform 21 in Roman numerals.
 21 = 20 + 1
 Roman Numerals = XX + I
 21 in Roman Numerals = XXI
1.  How to Write 21 in Roman Numerals? 
2.  Basic Rules 
3.  Numbers related to 21 
4.  FAQs on 21 in Roman Numerals 
How to Write 21 in Roman Numerals?
Roman numerals for 21 can be obtained by using the method given below:
In this method, we break 21 into the least expandable form, write their respective roman letter and add/subtract them, i.e. 21 = 10 + 10 + 1 = X + X + I = XXI.
Therefore, the value of 21 in roman numerals is XXI.
ā Also Check: Roman Numerals Calculator
Basic Rules to Interpret Roman Numerals
 When a bigger letter precedes a smaller letter, the letters are added. For example: MD, M > D, so MD = M + D = 1000 + 500 = 1500.
 When a smaller letter precedes a bigger letter, the letters are subtracted. For example: CD, C < D, so CD = D  C = 500  100 = 400.
 When a letter is repeated multiple times, they get added. For example: MMM = M + M + M = 1000 + 1000 + 1000 = 3000
 The same letter cannot be used more than three times in succession.
Roman Numerals for Numbers Related to 21
Roman numerals may seem different from numbers, but they are similar. For example, 21 in roman numerals is equivalent to XXI. The roman numerals for numbers related to 21 are given below:
 XX = 20
 XXI = 20 + 1 = 21
 XXII = 20 + 2 = 22
 XXIII = 20 + 3 = 23
 XXIV = 20 + 4 = 24
 XXV = 20 + 5 = 25
 XXVI = 20 + 6 = 26
 XXVII = 20 + 7 = 27
 XXVIII = 20 + 8 = 28
 XXIX = 20 + 9 = 29
21 in Roman Numerals Examples

Example 1: Find the Value of (17  36) + 21 in roman numerals.
Solution:
Solving (17  36) + 21 = 19 + 21 = 2. Now, we will write the answer, that is, 2 = II.

Example 2: Find the Difference Between 43 and 21 in Roman Numerals.
Solution:
Solving the given problem, 43  21 = 22
To determine the value of 43  21 in roman numerals, we will express 22 in the expanded form, i.e., 22 = 20 + 2 = XX + II = XXII. 
Example 3: What is the remainder when XXI is divided by XVIII?
Solution:
XVIII = 18 and XXI = 21 in numbers.
On dividing 21 by 18, it leaves a remainder of 3.
Now, 3 = III
Therefore, when XXI is divided by XVIII, the remainder is III. 
Example 4: Find the value of 3174  21.
Solution:
Solving the given problem, 3174  21 = 3153
To determine the value of 3174  21 in roman numerals, we will express 3153 in the expanded form, i.e. 3153 = 3000 + 100 + 50 + 3 = MMM + C + L + III = MMMCLIII.
FAQs on 21 in Roman Numerals
What does 21 in Roman Numerals Mean?
To write 21 in roman numerals, we will first express 21 in expanded form. 21 = 10 + 10 + 1 = X + X + I = XXI. Hence, 21 in roman numbers is expressed as XXI.
How do you Write the Number 21 in Roman Numerals?
To convert 21 in roman numerals, the conversion involves breaking the numbers based on place values (ones, tens, hundreds, thousands).
 Tens = 20 = XX
 Ones = 1 = I
 Number = 20 + 1 = XX + I = XXI
Why is 21 in Roman Numerals Written as XXI?
We know that in roman numerals, we write 1 as I, and 10 as X. Therefore, 21 in roman numerals is written as 21 = 20 + 1 = XX + I = XXI.
What Should be Added to 6 to Get 21? Write the answer in Roman numerals.
21 in roman numerals is XXI whereas 6 is VI. 21  6 = 15. Therefore, 15 should be added to 6 to get 21. Now, to convert 15 in roman numbers, we will express it in its expanded form, that is, 15 = 10 + 5 = X + V = XV.
What is the Value of (34  45) + 21 in Roman Numbers?
Solving (34  45) + 21 = 11 + 21 = 10. To express, (34  45) + 21 in roman numerals, we will write the answer, that is, 10 as X
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