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.