Last updated on May 26th, 2025
Roman numerals are a way of expressing numbers using symbols. I, V, X, L, C, D, and M are the symbols we use. Roman Numerals are used in royal titles, book names, sequences, and so on. Here we will be discussing Roman Numerals, rules, and examples.
The royal titles, such as Henry I, Henry II, and so on, use Roman numerals. Have you noticed the names and wondered what these symbols (I and II) represented? Those are the Roman Numerals.
Earlier, people used fingers, sticks, bones, etc., to count. As life became more complex, a standard form was required for counting. Ancient Romans used the Roman numeral system for this purpose. I (1), V (5), X (10), L (50), C (100), D (500), and M (1000) are the symbols we use to count.
In Roman Numerals, we use LXXVIII to represent 78. Here L is 50, X is 10, X is 10, V is 5, I is 1, and I is 1. Let’s learn more about Roman numerals and how we write them.
There are certain basic rules to write a number in Roman Numerals. In this section, let’s discuss some basic rules that need to be remembered when writing a number in Roman numerals.
The addition method is used when a smaller number is placed after a larger number. For example, LXXVIII → L + X + X + V + I + I + I → 50 + 10 + 10 + 5 + 1 + 1 + 1 = 78.
To write a large number, certain Roman Numerals can be repeated up to three times. For example, XXX → 30.
If a smaller number precedes a larger number in Roman Numerals, we subtract the smaller number from the larger number. For example, IX → X - I → 10 - 1 = 9.
Symbols cannot be repeated more than three times, and symbols like V, L, and D cannot be repeated. For example, we won't write LL for 100; instead, we use C. For 8, we write VIII, not IIIIIIII.
Let’s now learn how to write 78 in Roman Numerals. Follow these methods to write the number in Roman Numerals.
In the expansion method, based on the place value, the number is broken down. In this section, we will learn how to write 78 in Roman numerals using the expansion method.
To write 78 in Roman Numerals, follow these steps:
Step 1: Break the number based on place value. Place value includes ones, tens, hundreds, etc.
For 78, we write it as 50 + 10 + 10 + 5 + 3.
Step 2: Convert the numbers into Roman Numerals:
- 50 in Roman Numerals — L
- 10 in Roman Numerals — X
- 5 in Roman Numerals — V
- 3 in Roman Numerals — III
Step 3: Combine the Roman Numerals together.
Therefore, 78 in Roman Numerals is L (50) + X (10) + X (10) + V (5) + III (3) = LXXVIII.
When writing a large number in Roman Numerals, we group the numbers. To write 78 in Roman Numerals, we group 78 as 50 + 10 + 10 + 5 + 3.
- 50 in Roman Numerals — L
- 10 in Roman Numerals — X
- 5 in Roman Numerals — V
- 3 in Roman Numerals — III
So, 78 is written as LXXVIII in Roman Numerals.
Students often make mistakes when writing numbers in Roman Numerals. To master Roman Numerals, we can learn a few common mistakes and how to avoid them.
A historian is studying ancient manuscripts and finds that there were LXXX pages in one document and XVIII pages in another. What is the total number of pages in both documents?
The total number of pages in both documents is XCVIII.
LXXX = 80
XVIII = 18
80 + 18 = 98
98 in Roman Numerals is XCVIII.
A curator is arranging LXXVIII artifacts equally in IX display cases. How many artifacts will be in each display case?
Each display case will contain VIII artifacts.
LXXVIII = 78
IX = 9
78 / 9 = 8 R6
Each display case gets 8 artifacts, and 6 artifacts remain. 8 in Roman Numerals is VIII.
A mathematician challenges students to find the difference between CX and LXXVIII. What is the result?
The difference is XXXII.
CX = 110
LXXVIII = 78
110 - 78 = 32
32 in Roman Numerals is XXXII.
Convert the sum of XXXIX and XXXIX into Roman numerals.
The sum of XXXIX and XXXIX is LXXVIII.
XXXIX = 39
39 + 39 = 78
78 in Roman Numerals is LXXVIII.
An archaeologist has found a scroll mentioning LXXVIII coins to be divided among XIII people. How many coins does each person receive if the division is exact?
Each person receives VI coins.
LXXVIII = 78
XIII = 13
78 / 13 = 6
6 in Roman Numerals is VI.