What are the Rules for Roman numeral conversions? 

Rules for Roman numeral conversions

A specific number of systems that are used by letters to express numbers collectively indicate Roman numerals. In ancient times, Romans used the letters like I, V, X, L, C, D, and M to describe the numbers. At that time, the Roman letters were used for the objective of counting and performing other day-to-day transactions in finances. The Roman letters are made use of as general suffixes for the people over generations, as hour marks on a clock, to indicate the names of Popes and Monarchs, etc. Go through this blog post to understand the concept of Roman numerals and also explore the rules for Roman numbers.

What are Roman Numerals?

Generally, Roman numeral converter indicate a number system that was widely used until the late middle ages throughout Europe as the standard writing system. The ancient Romans described that when a number approaches 10 it is not easy to count on one’s fingers. That was the reason, there was a need to develop a proper number system that could be used for trade and communications in businesses. However, Modern Roman numerals contain 7 letters to explain different numbers. These letters include I, V, X, L, C, D, and M which represent the numbers 1, 5, 10, 50, 100, 500, and 1000 respectively.

Rules of Roman Numerals:

Let’s discuss the rules of Roman Numerals which are significant for reading and writing Roman numbers in order to avoid mistakes. Also Roman numeral converter make conversion of numerical numbers into roman numerals easily and quickly. Following are basic rules for Roman numerals. These are: 

Rule 1: When specific numerals are repeated, then the number indicated by them is their sum. For example, II = 1 + 1 = 2, or XX = 10 + 10 = 20, 

Rule 2: it is important to keep in mind that no Roman numerals can come together more than 3 times. For example, we cannot write 40 as XXXX

Rule 3: The letters of Romans Numerals such as V, L, and D are not repeated again and again.

Rule 4: Romans Numerals such as I, X, and C can be used as subtractive numerals. There can be 6 combinations when we subtract. These are IV = 5 – 1 = 4; IX = 10 – 1 = 9; XL = 50 – 10 = 40; XC = 100 – 10 = 90; CD = 500 – 100 = 400; and CM = 1000 – 100 = 900

Rule 5: When a Roman numeral of any value is placed after another Roman numeral of greater value, then the result becomes the sum of the numerals. For example, VIII = 5 + 1 + 1 + 1 = 8, or, XV = 10 + 5 = 15,

Rule 6: Similarly, when a Roman numeral of any value is placed before another Roman numeral of greater value, then the result is the difference between the numerals. For example, IV = 5 – 1 = 4, or, XL = 50 – 10 = 40, or XC = 100 – 10 = 90

Rule 7: When a Roman numeral of a smaller value is placed between two numerals of greater value, it is subtracted from the numeral on its right. For example, XIV = 10 + (5 – 1) = 14, or, XIX = 10 + (10 – 1) = 19

Rule 8: To multiply a number by a factor of 1000 a bar is placed over it.

Rule 9: Roman numerals do not follow any place value system.

Rule 10: There is no Roman numeral for zero (0).

How to Read Roman Numerals?

If you remember the rules given above, then you can easily read Roman numerals. If you do not understand roman numerals then use roman numeral converter for translating them. However, a simple and ideal method to write the Roman numerals in Hindu-Arabic numbers is to expand the Roman number and then add all of them together. For example, if we have XVII, we can expand and add them as, X + V + I + I = 10 + 5 + 1 + 1 = 17.

Let us read and write Roman numerals with the help of a few examples.

Example 1: What is LVI in Roman numerals?

Solution: As we know that L = 50, V = 5, and I = 1. So first of all we will expand and add the values of all the letters. This will be L + V + I = 50 + 5 + 1 = 56.

Example 2: What does XXVI mean in numbers?

Solution: As we know the values of X = 10 and V = 5, and I = 1. Therefore, you have to  expand the values and then add them as X + X + V + I = 10 + 10 + 5 + 1 = 26.