How to Read Roman Numerals

At the end of a twentieth century movie or on the cornerstone of a building you may encounter complicated dates. Here's how to read modern Roman Numerals.

Difficulty Level: average      Time Required: 5 minutes

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Here's How:

1. Learn the meanings of the letters: M=1000, D=500, C=100, L=50, V=5, and I=1.
2. The letters (Roman numerals) are arranged from left to right in descending order of valuation and are simply added to each other (MDCLXVI = 1000 + 500 + 100 + 50 + 10 + 5 + 1 = 1666), but...
3. Sometimes there's a lower value numeral in front of (to the left of) a higher value numeral to indicate that the lower value should be subtracted from the adjacent higher value (XL = ten taken from fifty = 40).
4. This subtraction rule is particularly useful in modern notations where we avoid four or more identical, consecutive numerals. Thus, instead of writing IIII, we write IV.
5. There are a few more rules or rather non-standardized styles that apply to ancient numerals. "9" could be written "VIIII."
6. A smaller numeral to the left of a larger could mean multiplication (VM = 5000).
7. Occasionally two smaller numerals to the left are to be subtracted from the sum of those to the right (IIXX = 18).
8. An oversized terminal I could mean the "1" should be doubled (MCMVI = 1907).
   

Tips:

1. In modern usage, the smaller value to be subtracted from the larger is one Roman Numeral unit smaller than the numeral to the right. Thus, instead of writing "IMM" for "1999," we have to read/translate the cumbersome MCMXCIX (1000 + [1000 - 100] + [100 - 10] + [10 - 1]).
   

Related Features:

• Roman Numerals
• Latin Numbers
• Latin Counting Numbers and Italian Counting Numbers