CDXX Roman Numerals
CDXX Roman Numerals can be written as numbers by combining the transformed roman numerals i.e. CDXX = (D  C) + X + X = (500  100) + 10 + 10 = 420. The higher roman numerals precede the lower numerals resulting in the correct translation of CDXX Roman Numerals. In this article, we will explain how to convert CDXX Roman numerals in the correct number translation.
 CDXX = CD + XX
 CDXX = 400 + 20
 CDXX = 420
How to Write CDXX Roman Numerals?
The numerical value of CDXX Roman Numerals can be obtained by using any of the two methods given below:
Method 1: In this method, we break the roman numerals into single letters, write the numerical value of each letter and add/subtract them.
 CDXX = (D  C) + X + X = (500  100) + 10 + 10 = 420
Method 2: In this method, we consider the groups of roman numerals for addition or subtraction such as,
 CDXX = CD + XX = 400 + 20 = 420
Therefore, the numerical value of CDXX roman numerals is 420.
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What are the Basic Rules to Write Roman Numerals?
 When a bigger letter precedes a smaller letter, the letters are added. For example: DI, D > I, so DI = D + I = 500 + 1 = 501
 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 2 or 3 times, they get added. For example: XXX = X + X + X = 10 + 10 + 10 = 30
 The same letter cannot be used more than three times in succession.
Numbers Related to CDXX Roman Numerals
Roman numerals were used in ancient Rome and utilized combinations of letters using the Latin alphabets I, V, X, L, C, D, and M. It may seem different than numbers, but they are similar. For example, CDXX Roman numerals are equivalent to the number 420. The roman numerals related to CDXX are given below:
 CDXX = 400 + 20 = 420
 CDXXI = 400 + 20 + 1 = 421
 CDXXII = 400 + 20 + 2 = 422
 CDXXIII = 400 + 20 + 3 = 423
 CDXXIV = 400 + 20 + 4 = 424
 CDXXV = 400 + 20 + 5 = 425
 CDXXVI = 400 + 20 + 6 = 426
 CDXXVII = 400 + 20 + 7 = 427
 CDXXVIII = 400 + 20 + 8 = 428
 CDXXIX = 400 + 20 + 9 = 429
CDXX Roman Numerals Examples

Example 1: Find the Difference Between CDXX and CCCXXXVI.
Solution:
Roman Numeral CDXX is equal to 420 and CCCXXXVI is 336.
Now, CDXX  CCCXXXVI = 420  336 = 84
Since, 84 = LXXXIV
Therefore, CDXX  CCCXXXVI = LXXXIV 
Example 3: Find the Product of Roman Numerals CDXX and IX.
Solution:
CDXX = 400 + 20 = 420 and IX = 9
Now, CDXX × IX = 420 × 9 = 3780
Since, MMMDCCLXXX = 3000 + 700 + 80 = 3780
Therefore, CDXX × IX = MMMDCCLXXX 
Example 4: Find the Sum of CLXXVII and CDXX Roman Numerals.
Solution:
CLXXVII = 100 + 70 + 7 = 177 and CDXX = 400 + 20 = 420
Now, CLXXVII + CDXX = 177 + 420 = 597
Since, DXCVII = 500 + 90 + 7 = 597
Therefore, the sum of CLXXVII and CDXX roman numerals is DXCVII
FAQs on CDXX Roman Numerals
What does CDXX Roman Numerals Mean?
We will write CDXX Roman numerals in the expanded form to determine its value. CDXX = (D  C) + X + X = (500  100) + 10 + 10 = 420. Hence, the value of Roman Numerals CDXX is 420.
What is the Remainder when CDXX is Divided by IX?
CDXX = 420 and IX = 9 in numbers. On dividing 420 by 9, it leaves a remainder of 9. Now, 6 = VI Therefore, when CDXX is divided by IX, the remainder is VI.
What Should be Added to Roman Numerals CDXX to Get MMMDCIX?
First, we will write MMMDCIX and CDXX in numbers, i.e. CDXX = 420 and MMMDCIX = 3609. Now, 3609  420 = 3189. And, 3189 = MMMCLXXXIX. Therefore, MMMCLXXXIX should be added to 420 roman numerals to get MMMDCIX.
How is Roman Numerals CDXX Written in Numbers?
To convert CDXX Roman Numerals to numbers, the conversion involves breaking the Roman numerals on the basis of place values (ones, tens, hundreds, thousands), like this:
 Hundreds = 400 = CD
 Tens = 20 = XX
 Number = 420 = CDXX
Why is 420 Written in Roman Numerals as CDXX?
We know that in roman numerals, we write 10 as X, and 400 as CD. Therefore, 420 in roman numerals is written as CDXX = CD + XX = 400 + 20 = CDXX.
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