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 utilized in royal titles, book names, sequences, and more. Here we will discuss Roman numerals, rules, and examples.
Royal titles, such as Henry I, Henry II, and so on, use Roman numerals. Have you noticed the names and wondered what these symbols represent? Those are Roman numerals.
In earlier times, people counted using fingers, sticks, bones, and more. As life became complex, a standard form was required for counting. Ancient Romans used the Roman numeral system to count. 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 MCMXL to represent 1940. Here, M is 1000, CM is 900, and XL is 40. Let’s learn more about Roman numerals and how we write them.
There are certain basic rules for writing 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 the smaller number is placed after the larger number. For example, VI → V + I → 5 + 1 = 6.
To write a large number, certain Roman numerals can be repeated up to three times. For example, III → 3.
If a small number is followed by a large number in Roman numerals, we subtract the smaller number from the larger number. For example, IX → X - I → 10 - 1 = 9.
The symbols cannot be repeated more than three times, and some symbols like V, L, and D cannot be repeated. For example, we won't write VV for 10; instead, we use X, and for 8, we write VIII not IIIIIIII.
Let’s now learn how to write 1940 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 1940 in Roman numerals using the expansion method. To write 1940 in Roman numerals, follow the steps:
Step 1: Break the number based on place value: thousands, hundreds, tens, and ones. For 1940, we write it as 1000 + 900 + 40.
Step 2: Convert each number into Roman numerals:
Step 3: Combine the Roman numerals together. Therefore, 1940 in Roman numerals is M (1000) + CM (900) + XL (40) = MCMXL
When writing a large number into Roman numerals, we group the number. To write 1940 in Roman numerals, we group 1940 as 1000 + 900 + 40.
So, 1940 is written as MCMXL 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 ways to avoid them.
Convert the year when World War II ended, MCMXLV, to the year when it started using subtraction.
The year World War II started is MCMXXXIX.
World War II ended in year MCMXLV, which is 1945 in numbers. To find the year it started, we subtract 6 years (1945 - 1939 = 6).
MCMXLV - VI = MCMXXXIX.
1945 - 6 = 1939.
Thus, the Roman numeral for the year 1939 is MCMXXXIX.
An archaeologist discovered a scroll dated MCMXL in Roman numerals. How many years have passed since that year to the year MMXXIII?
The number of years that have passed is LXXXIII.
To find out how many years have passed, we subtract the earlier year from the later year.
MMXXIII = 2023
MCMXL = 1940
2023 - 1940 = 83
83 in Roman numerals is LXXXIII.
Therefore, LXXXIII years have passed since MCMXL.
A historian is cataloguing events from the 20th century and finds that she has to place events from MCMXL between the years MCMXXXV and MCMXLV. What is the average year of these events in Roman numerals?
The average year of these events is MCMXL.
To find the average year, we add all the years together and divide by the number of years.
MCMXXXV = 1935
MCMXL = 1940
MCMXLV = 1945
Average = (1935 + 1940 + 1945) / 3 = 5810 / 3 = 1940
The average year is 1940, which is MCMXL in Roman numerals.
What is the sum of the Roman numerals for the years MCMXL and MCML?
The sum of the Roman numerals for the years MCMXL and MCML is MMMCMXC.
MCMXL = 1940
MCML = 1950
1940 + 1950 = 3890
3890 in Roman numerals is MMMCMXC. Thus, the sum is MMMCMXC.
If a movie was set in the year MCMXL and the sequel was set XX years later, what year does the sequel take place in Roman numerals?
The sequel takes place in the year MCMLX.
MCMXL = 1940
XX = 20
1940 + 20 = 1960
1960 in Roman numerals is MCMLX.
Therefore, the sequel takes place in the year MCMLX.
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.
: She loves to read number jokes and games.