179 LearnersLast updated on May 26th, 2025
CMLXXXVII in Roman Numerals
To meet their daily commerce and administration needs, the ancient Romans developed Roman numerals. They used a combination of seven symbols — I, V, X, L, C, D, and M to represent numbers. Roman numerals were used to record transactions, keep track of data, and label military units. In this topic, we are going to learn about the Roman numeral CMLXXXVII.
What is 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.
Basic Rules for CMLXXXVII in Roman Numerals
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.
How to Write CMLXXXVII in Roman Numerals?
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
CMLXXXVII in Roman Numeral by Expansion 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.
CMLXXXVII in Roman Numeral by Grouping Method
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.
Numbers Related to CMLXXXVII in Roman Numerals
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:
| Number | Roman Numeral | Breakdown |
|---|---|---|
| 980 | CMLXXX | 900 + 80 = 980 |
| 981 | CMLXXXI | 900 + 80 + 1 = 981 |
| 982 | CMLXXXII | 900 + 80 + 2 = 982 |
| 983 | CMLXXXIII | 900 + 80 + 3 = 983 |
| 984 | CMLXXXIV | 900 + 80 + 4 = 984 |
| 985 | CMLXXXV | 900 + 80 + 5 = 985 |
| 986 | CMLXXXVI | 900 + 80 + 6 = 986 |
| 987 | CMLXXXVII | 900 + 80 + 7 = 987 |
| 988 | CMLXXXVIII | 900 + 80 + 8 = 988 |
| 989 | CMLXXXIX | 900 + 80 + 9 = 989 |
Common Mistakes and How to Avoid Them in CMLXXXVII Roman Numerals
Students can make mistakes when studying Roman numerals. Here are a few common mistakes students make, and ways to avoid them.
Mistake 1
Mistakes when applying the repetition method
It can be quite confusing for beginners to remember that Roman numerals cannot be repeated more than three times. Another thing to keep in mind is that Roman numerals such as V, L, and D cannot be repeated.
For example, writing LL as 100 is incorrect; the correct answer is C.
Mistake 2
Not subtracting the numerals correctly
The subtraction method is used when a smaller symbol follows a larger symbol. One should also remember that only specific symbols can be subtracted, like I and X.
For example, IL instead of XLIX for the number 49.
Mistake 3
Not grouping the numbers correctly.
When writing Roman numerals, we need to group the numbers correctly.
For example, the number 15 is 10 (X) + 5 (V).
Mistake 4
Confusing similar-looking symbols for other numbers
Certain numerals have different numbers when placed in a different order. So we must make sure to fully understand the order of certain symbols and their placements. All symbols have to be placed in a different order to represent the correct number.
For example, IV (4) and VI (6) have the same symbols but are in different orders.
Mistake 5
Not counting all numbers when writing in Roman numerals.
Forgetting to count all numbers, when doing the expansion method or grouping method, can lead to mistakes.
For example, writing CM (900) and forgetting LXXXVII (87) for 987.
Recheck steps once done during any arithmetic operation.
CMLXXXVII Roman Numerals Examples
Problem 1
You have a collection of CMLXXXVII coins. You find another CLXVIII coins. How many coins do you have in total? Provide the answer in Roman numerals.
The total is MCLV
Explanation
Convert both Roman numerals into their decimal form: CMLXXXVII = 987
CLXVIII = 168
Now add both numbers: 987 + 168 = 1155
Convert 1155 into Roman numerals: 1155 = 1000 (M) + 100 (C) + 50 (L) + 5 (V) = MCLV
Problem 2
If you have a ribbon that is CMLXXXVII cm long and you cut off DLIII cm, how much ribbon is left? Provide the answer in Roman numerals.
The remaining length is CDXXXIV
Explanation
Convert the Roman numerals into their decimal form: CMLXXXVII = 987
DLIII = 553
Now subtract the numbers: 987 - 553 = 434
Convert 434 into Roman numerals: 434 = 400 (CD) + 30 (XXX) + 4 (IV) = CDXXXIV
Problem 3
What is one-third of CMLXXXVII? Give the answer in Roman numerals.
CCCXXIX
Explanation
Convert CMLXXXVII into its decimal form: CMLXXXVII = 987
Divide by 3: 987 / 3 = 329
Convert 329 into Roman numerals: 329 = 300 (CCC) + 20 (XX) + 9 (IX) = CCCXXIX
Problem 4
Calculate the product of CMLXXXVII and III. Provide the answer in Roman numerals.
The product is MMCMXLI
Explanation
Convert CMLXXXVII and III into numbers: CMLXXXVII = 987
III = 3
Multiply the numbers: 987 × 3 = 2961
Convert 2961 into Roman numerals: 2961 = 2000 (MM) + 900 (CM) + 60 (LX) + 1 (I) = MMCMXLI
Problem 5
Convert CMLXXXVII into its decimal form.
In decimal form, CMLXXXVII is 987
Explanation
Break CMLXXXVII into components: CM = 900
LXXX = 80 (L + X + X + X)
VII = 7 (V + I + I)
Add values: 900 + 80 + 7 = 987
FAQs on CMLXXXVII in Roman Numerals
1.What is LXXXVII in Roman numerals?
2.Is CMLXXXVII a prime number?
3.What is CMLXXXVII + CMLXXXVII?
4.What is CMXC?
5.Subtract LXXXVII from CMLXXXVII
6.How can children in India use numbers in everyday life to understand CMLXXXVII in Roman Numerals?
7.What are some fun ways kids in India can practice CMLXXXVII in Roman Numerals with numbers?
8.What role do numbers and CMLXXXVII in Roman Numerals play in helping children in India develop problem-solving skills?
9.How can families in India create number-rich environments to improve CMLXXXVII in Roman Numerals skills?
Important Glossaries for CMLXXXVII in Roman Numerals
- 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.
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Hiralee Lalitkumar Makwana
About the Author
Hiralee Lalitkumar Makwana has almost two years of teaching experience. She is a number ninja as she loves numbers. Her interest in numbers can be seen in the way she cracks math puzzles and hidden patterns.
Fun Fact
: She loves to read number jokes and games.
