CMLXXXVII in Roman Numerals

Ancient Romans discovered that counting fingers could get very complicated after 10. To overcome this complexity, the Roman numeric system was developed.

This was widely used throughout Europe as a standard writing system until the late Middle Ages. Seven symbols represent numbers in the Roman numeric system — I, V, X, L, C, D, and M.

The numerals consist of different combinations of these symbols. CMLXXXVII in Roman numerals can be written in number form by adding the values of each Roman numeral, i.e., CMLXXXVII = 987.

Let us learn more about the Roman numeral CMLXXXVII, how we write it, the mistakes we usually make, and ways to avoid these mistakes.

When writing Roman numerals, there are a few rules that we need to follow based on the numerals we are trying to write. In this section, we will learn about the rules when writing Roman numerals and how to represent them.

Rule 1: Addition Method:

When a larger symbol is followed by a smaller symbol, we add the numerals to each other. For example, in VIII, we have 5 + 3 = 8.

Rule 2: Repetition Method:

A symbol that is repeated three times in continuation increases the numeral's value. For example, XXX = 30.

Rule 3: Subtraction Method:

We use the subtraction method when a larger symbol follows a smaller symbol. For example, XL = 40 (which is 50 – 10).

Rule 4: Limitation Rule:

Symbols cannot be repeated more than three times, and some symbols, such as V, L, and D, cannot be repeated more than once. For example, 10 is represented as X and not VV.

Let us learn how to write CMLXXXVII in Roman numerals. There are two methods that we can use to write Roman numerals:

• By Expansion Method
• By Grouping Method

The breaking down of Roman numerals into parts and then converting them into numerals is what we call the expansion method. The expansion method involves breaking down Roman numerals into numerical form and adding them to get the final number.

Step 1: Break the Roman numerals into parts.

Step 2: Write each Roman numeral with its numerical digit in the place value.

Step 3: Add the numerals together. For CMLXXXVII,

Step 1: First, we break the Roman numerals. CMLXXXVII = CM + L + X + X + X + V + I + I

Step 2: Write the Roman numerals for each part. The Roman Numeral CM is 900 The Roman Numeral L is 50 The Roman Numeral X is 10 The Roman Numeral V is 5 The Roman Numeral I is 1

Step 3: Combine all the numbers. CM + L + X + X + X + V + I + I = 900 + 50 + 10 + 10 + 10 + 5 + 1 + 1 = 987. Therefore, the Roman Numeral CMLXXXVII is 987.

Using subtraction and addition rules, we will apply the grouping method. This means we break the Roman numerals into smaller groups, making it easier to work with. This method groups the Roman numerals logically, and then we write the numbers for each group.

Step 1: Take the largest number and write the number for that Roman numeral.

Step 2: Write the Roman numeral using the subtraction and addition rules. Example: Let’s take the Roman numeral CMLXXXVII.

Step 1: The larger Roman numerals are what we will begin with. Once split, the Roman numerals we get are CM, LXXX, and VII. The numeral for CM is 900.

Step 2: Now we need to either add or subtract the smaller number, depending on its place. Here we add LXXX and VII to CM, and we will get CMLXXXVII. The Roman numeral LXXX is 80. The Roman numeral VII is 7. Therefore, the numeral of CMLXXXVII is 987.

We follow a pattern when it comes to writing Roman numerals. In this section, we will write some numbers related to the Roman numeral CMLXXXVII: 

• Limitation Rule: There are some symbols that cannot be repeated more than once (V, L, D). For example, LVV for 60 is wrong; the correct answer is LX.

• Place value: The position of a digit in a number; this position determines its value. For example, the number 9 in 987 is in the hundred's place.

• Subtraction Method: Used when a smaller symbol precedes a larger one to indicate subtraction. For example, IV (4) is 5 - 1.

• Addition Method: Used when a smaller symbol follows a larger one to indicate addition. For example, VI (6) is 5 + 1.

• Roman Numeral System: An ancient numeral system using combinations of letters from the Latin alphabet (I, V, X, L, C, D, M) to signify values.