XLII, XLV, XXV, And XCLX Roman Numerals In Numbers

In this article, I will show how to convert XLII, XLV, XXV, and XCLX Roman Numerals in numbers. I have done some examples and I made it clear that these are the numbers that were used in ancient Rome, which are in base ten and comprise of Latin alphabet (I, V, X, L, C, D and M).

Before I proceed, I will like to take you through the basic rule, this will help your understanding as I solve the examples above.

Basic Roman Numerals Rule

  • If a bigger letter precedes or comes before a smaller letter, the letters are added. For example: LV = 50 + 5 = 55
  • If a smaller letter precedes a bigger letter, the letters are subtracted. For example XC = 100 – 10 = 90
  • If a letter is repeated 2 or 3 times, they are added. For example: XXX = X + X + X = 10 + 10 + 10 = 30
  • The same letter cannot be used more than three times in succession.

XLII, XLV, XXV, and XCLX Roman Numerals

XLII Roman Numeral in Number

XLII = XL + I + I (note XL = 50 – 10 = 40)

The reason why I put XL together is that a smaller number comes before a bigger number

XLII = 40 + 1 + 1 = 42

XLV Roman Numeral in Number

XLV = XL + V (note XL is 40 and V is 5)

XLV = 40 + 5 = 45

XXV Roman Numeral in Number

XXV = X + X + V = 10 + 10 + 5 = 25

XCLX Roman Numeral in Number

This is not a valid Roman Numeral because the numerals L and x may not follow a group of numerals in subtractive notation i.e. L and X can’t follow XC

In conclusion, the tabular representation will be shown below.

Roman NumeralsNumber
XCLXNot valid


Bolarinwa Olajire

A tutor with a demonstrated history of working in the education industry. Skilled in analytical skills. Strong education professional with a M. SC focused in condensed matter. You can follow me on Twitter by clicking on the icon below to ask questions.
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