Last updated on May 26th, 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 MCMLXXIX.
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. MCMLXXIX in Roman numerals can be written in number form by adding the values of each Roman numeral, i.e., MCMLXXIX = 1979.
Let us learn more about the Roman numeral MCMLXXIX, 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 MCMLXXIX 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 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 MCMLXXIX,
Step 1: First, we break the Roman numerals. MCMLXXIX = M + CM + L + X + X + IX
Step 2: Write the Roman Numerals for each part. The Roman Numeral M is 1000 The Roman Numeral CM is 900 The Roman Numeral L is 50 The Roman Numeral X is 10 The Roman Numeral IX is 9
Step 3: Combine all the numbers M + CM + L + X + X + IX = 1000 + 900 + 50 + 10 + 10 + 9 = 1979. Therefore, the Roman Numeral MCMLXXIX is 1979.
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 MCMLXXIX.
Step 1: The larger Roman numerals are what we will begin with. Once split, the Roman numerals we get are M, CM, L, XX, and IX. The numeral for M is 1000 The numeral for CM is 900 The numeral for L is 50 The numeral for XX is 20 The numeral for IX is 9
Step 2: Now we need to either add or subtract the smaller number, depending on its place.
Here we add CM, L, XX, and IX to M, and we will get MCMLXXIX. Therefore, the numeral of MCMLXXIX is 1979.
Students can make mistakes when studying Roman numerals. Here are a few common mistakes students make, and ways to avoid them.
What is the result of adding MCMLXXIX to XLII? Write the answer in Roman numerals.
The result is MMXXI
Convert both Roman numerals into decimal form:
MCMLXXIX = 1979
XLII = 42
Add the numbers: 1979 + 42 = 2021
Convert the number into Roman numerals: 2021 = 2000 (MM) + 20 (XX) + 1 (I) = MMXXI
Subtract CCCL from MCMLXXIX and express the result in Roman numerals.
The result is MDCXXIX
Convert the Roman numerals into decimal form:
MCMLXXIX = 1979
CCCL = 350
Subtract the numbers: 1979 - 350 = 1629
Convert 1629 into Roman numerals: 1629 = 1000 (M) + 600 (DC) + 20 (XX) + 9 (IX) = MDCXXIX
If you divide MCMLXXIX by III, what is the result in Roman numerals?
DCLXVI
Convert MCMLXXIX into decimal form:
MCMLXXIX = 1979
Divide by 3: 1979 / 3 = 659.6667 (rounded to nearest integer 660)
Convert 660 into Roman numerals: 660 = 500 (D) + 100 (C) + 60 (LX) = DCLX
Multiply MCMLXXIX by II and express in Roman numerals.
MMMCMXLVIII
Convert MCMLXXIX into decimal form:
MCMLXXIX = 1979
Multiply the numbers: 1979 × 2 = 3958
Convert 3958 into Roman numerals: 3958 = 3000 (MMM) + 900 (CM) + 50 (L) + 8 (VIII) = MMMCMXLVIII
Convert MCMLXXIX into its decimal form.
In decimal form, MCMLXXIX is 1979
Break MCMLXXIX into components:
M = 1000
CM = 900
LXX = 70
IX = 9
Add the values: 1000 + 900 + 70 + 9 = 1979
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.