LXXXVII Roman Numerals

LXXXVII Roman numerals represent the number 87. The Roman numeral LXXXVII is written using the Roman numerals L (50), X (10), V (5), and I (1). To convert LXXXVII Roman numerals to 87, we express LXXXVII in its expanded form, i.e., LXXXVII = L + X + X + X + V + I + I. Replacing the Roman numerals with their respective values, we have L + X + X + X + V + I + I = 50 + 10 + 10 + 10 + 5 + 1 + 1 = 87.
In this article, we will explain how to convert LXXXVII Roman numerals to Arabic numerals that we use daily, along with rules and examples.

Table of Contents

• How to Write LXXXVII Roman Numerals in Numbers?
• Numbers Related to LXXXVII Roman Numerals
• Basic Rules for Writing Roman Numerals
• Facts About LXXXVII Roman Numerals
• Solved Examples on LXXXVII Roman Numerals
• Practice Questions on LXXXVII Roman Numerals
• Conclusion

How to Write LXXXVII Roman Numerals in Numbers?

In this section, you will understand how to convert LXXXVII Roman numerals into their numerical value using two methods.



Method 1: Expansion method
First, we break down LXXXVII into
LXXXVII = L + X + X +  X + V + I + I
The Roman numeral MMXVII is formed by combining four symbols:

• L stands for 50

• X stands for 10

• V stands for 5

• I stands for 1 

• Now, add the values together:
  LXXXVII = L + X + X +  X + V + I + I
  = 50 + 10 + 10 + 10 + 5 + 1 + 1
  = 87
  So, the numerical value of the Roman numeral LXXXVII is 87

Method 2: Grouping method
To write LXXXVII Roman numerals in numbers using the grouping method, we break them into groups.
LXXXVII = L + XXX + VII

• L = 50

• XXX = 10 + 10 + 10 = 30

• VII = 5 + 1 + 1 = 7
  Now add the groups, and we get
  L + XXX + VII = 50 + 10 + 10 + 10 + 7 = 87
  i.e., the Roman numeral LXXXVII is equal to the number 87.

Numbers Related to LXXXVII Roman Numerals

Roman Numeral	Roman Numeral Expression	Expanded form	Number
LXXX	L + X + X + X	50 + 10 + 10 + 10	80
LXXXI	L + X + X + X + I	50 + 10 + 10 + 10 + 1	81
LXXXII	L + X + X + X + I + I	50 + 10 + 10 + 10 + 1 + 1	82
LXXXIII	L + X + X + X + I + I + I	50 + 10 + 10 + 10  + 1 + 1 + 1	83
LXXXIV	L + X + X + X + (V - I )	50 + 10 + 10 + 10 + (5 - 1)	84
LXXXV	L + X + X + X + V	50 + 10 + 10 + 10 + 5	85
LXXXVI	L + X + X + X + V + I	50 + 10 + 10 + 10 + 5 + 1	86
LXXXVII	L + X + X + X + V + I + I	50 + 10 + 10 + 10 + 5 + 1 + 1	87
LXXXVIII	L + X + X + X + V + I + I + I	50 + 10 + 10 + 10 + 5 + 1 + 1 + 1	88
LXXXIX	L + X + X + X + (X - I )	50 + 10 + 10 + 10 + (10 - 1)	89
XC	C - X	100 - 10	90

Basic Rules for Writing Roman Numerals

• Subtraction rule: When a smaller numeral precedes a bigger numeral, subtract the smaller value.
  Example: In LXXXIV, IV = (5 - 1) = 4

• Addition rule: When a bigger numeral precedes a smaller numeral, the values are added.
  Example: In LXXXVII, L > X > V > I; hence, we simply add the values of the numerals together.

• When a symbol is repeated successively, the values are added
  Example: In LXXXVII, the letters 'X' and 'I' are repeated. XXX = X + X + X = 10 + 10 + 10 = 30. The same symbol cannot be repeated more than three times in succession. Symbols V, L, and D cannot be repeated.

Facts About LXXXVII Roman numerals

Here is a simple and easy explanation of the key facts about LXXXVII in Roman numerals:

• LXXXVII  Roman numerals is equal to 87. It is written using four distinct Roman symbols: L (50), X (10), V (5), and I (1).

• The Roman numeral LXXXVII represents 87, which is an odd composite number with factors 1, 3, 29, and 87.

• LXXXVII is a semiprime number, as it can be represented as a product of two prime numbers, 3 and 29.

• LXXXVII only uses additive notation and does not use subtractive notation. LXXXVII = L(50) + X(10) + X(10) + X(10) + V(5) + I(1) + I(1). It is written entirely by adding values.

• No subtractive notation is used in Roman numeral LXXXVII.

• The Roman numeral LXXXVII follows the repetition rule. The symbols X (10) and I (1) are repeated. The repetition rule in Roman numerals states that a symbol can be repeated up to 3 times successively. However, symbols V, L, and D cannot be repeated.

Solved Examples on LXXXVII Roman Numerals

Example 1: Find the value of LXXXVII in Roman numerals in numbers.
Solution:L = 50, X = 10 , V = 5, I = 1
Using expansion method, LXXXVII = L + X + X + X + V + I + I
 = 50 + 10 + 10 + 10 + 5 + 1 + 1
= 87
LXXXVII Roman numerals is equivalent to 87.

Example 2: Write 87 in Roman numerals.
Solution: Break down 87 into 80 + 7 = 50 + 10 + 10 + 10 + 5 + 1 + 1
L = 50, X = 10 , V = 5, I = 1
Combining the symbols, we get 50 + 10 + 10 + 10 + 5 + 1 + 1 = L + X + X + X + V + I + I = LXXXVII
87 in Roman numerals is LXXXVII.

Example 3: LXXXVII - XVII = _______.
Solution: Converting to numbers, LXXXVII = 87 and XVII = 17
LXXXVII - XVII = 87 - 17 = 70
70 in Roman numerals is LXX.
Hence, LXXXVII - XVII = LXX

Example 4: A library had LXXXVII books. It bought XIII more books. How many books are there now?
Solution: the library had LXXXVII books, i.e., 87 books. It bought XIII more books. Now the library has LXXXVII + XIII = 87 + 13 = 100 books.

Example 5. LXXXVII × II = ____.
Solution:  LXXXVII × II = 87 × 2 = 174
174 in Roman numerals is CLXXIV
LXXXVII × II = CLXXIV

Practice Questions on LXXXVII Roman Numerals

1. What is the value of LXXXVII in numbers?

2. Write 87 in Roman numerals.

3. An event happened in the year LXXXVII (87 AD). After 15 years, what year was it?

4. What is the remainder when LXXXVII is divided by XI.

5. Write three Roman numerals before and after LXXXVII.

Conclusion

LXXXVII is not just a number written differently. It represents a traditional numbering system that is still meaningful and widely used in modern society in books, movie sequels, building cornerstones, clock faces, etc. Learning the conversion of the Roman numeral LXXXVII to the Arabic numeral 87 enhances comprehension of Roman numerals, strengthens problem-solving skills, and reinforces the historical foundations of mathematics. 

Learn LXXXVII Roman numerals in a simple and student-friendly way at Orchids International School.