Table Of Contents
Last updated on March 1st, 2025
To meet their daily commerce and administration needs, the ancient Romans developed Roman Numerals. It 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 CMX.
Ancient Romans discovered that counting fingers could get very complicated after 10. So to overcome the 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 are used to represent numbers in the Roman numeric system — I, V, X, L, C, D, and M. The numerals are made up of different combinations of these symbols. CMX in Roman numerals can be written in number form by adding and subtracting the values of each Roman numeral, i.e., CMX = 910.
Let us learn more about the Roman numeral CMX, how we write them, 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 Roman numerals we are trying to write. In this section, we will learn about the rules when writing Roman numerals and how to represent them.
A symbol that is repeated three times in continuation increases the value of the numeral. For example, XXX = 30.
We use the subtraction method when a larger symbol follows a smaller symbol. For example, XL = 40 (which is 50 – 10).
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 about how to write CMX in Roman numerals. There are two methods that we can use to write Roman numerals:
The breaking down of Roman numerals into parts and then converting them into numerals is what we call the expansion method. The expansion method is the breaking down of Roman numerals into numerical form and adding or subtracting them to get the final number.
Step 1: Break the Roman numerals into parts.
Step 2: Now write each of the Roman numerals with its numerical digit in the place value.
Step 3: Add the numerals together.
For CMX,
Step 1: First, we break the Roman numerals. CMX = C + M + X
Step 2: Write the Roman Numerals for each part The Roman Numeral C is 100 The Roman Numeral M is 1000 The Roman Numeral X is 10
Step 3: Combine all the numbers Since C is before M, we subtract it: 1000 - 100 = 900 Then add X: 900 + 10 = 910 Therefore, the Roman Numeral CMX is 910.
Using subtraction and addition rules, we will apply the grouping method. This means we break the Roman numerals into smaller groups, which makes 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 CMX.
Step 1: The larger Roman numerals are what we will begin with. Once split, the Roman numerals we get are CM and X. 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 X to CM, and we will get CMX. The Roman numeral X is 10. Therefore, the numeral of CMX is 910.
A Roman architect designed a coliseum with CMX seats in one section and DC seats in another. How many seats are there in total? Write the answer in Roman numerals.
An artifact was found with the inscription CMX. If 200 years have passed since it was created, what was the original year inscribed on the artifact? Write the original year in Roman numerals.
A historian is cataloging ancient coins and finds a chest with CMX coins. If they are divided equally among 5 museums, how many coins does each museum receive? Write the answer in Roman numerals.
A scribe wrote CMX pages in one month and plans to write twice as many next month. How many pages will he have written in total by the end of the second month? Write the answer in Roman numerals.
Convert CMX into its decimal form.
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.