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Last updated on April 1st, 2025
Roman numerals are the 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. Have you noticed the names and wondered what these symbols (I and II) represented? Those are the Roman Numerals. Earlier people used to count using fingers, sticks, bones, etc., to count earlier. When life became complex, a standard form was required to count. 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 CXXIII to represent 123, where C is 100, X is 10, 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.
Rule 1: Addition Method
The addition method is used when the smaller number is placed after the larger number. For example, CXXIII → C + X + X + I + I + I → 100 + 10 + 10 + 1 + 1 + 1 = 123.
Rule 2: Repetition Method
To write a large number, certain Roman Numerals can be repeated up to three times. III → 3.
Rule 3: Subtraction Method
If a small number is followed by a large number in Roman Numerals, we subtract the smaller number from the large number. For example, IX → X - I → 10 - 1 = 9.
Rule 4: Limitation Rule
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 123 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 123 in Roman numerals using the expansion method.
To write 123 in Roman Numerals, follow the steps:
Step 1: Break the number down based on place value: ones, tens, hundreds, etc.
For 123, we write it as 100 + 20 + 3.
Step 2: Convert the number into Roman Numerals:
100 in Roman Numerals — C
20 in Roman Numerals — XX
3 in Roman Numerals — III
Step 3: Combine the Roman Numerals together:
Therefore, 123 in Roman Numerals is C (100) + XX (20) + III (3) = CXXIII.
When writing a large number into Roman Numerals, we group the number.
To write 123 in Roman Numerals, we group 123 as 100 + 20 + 3.
100 in Roman Numerals — C
20 in Roman Numerals — XX
3 in Roman Numerals — III
So, 123 is written as CXXIII in Roman Numerals.
A historian is studying ancient texts and finds two references: one mentioning the year LXXXIX and another mentioning the year XXXIV. What is the difference in years between these two references?
An architect is designing a building with CLXIII windows distributed evenly across XIII floors. How many windows are on each floor?
A treasure map indicates two coordinates: first marked as CXLV paces and the second as XXIII paces. What is the total number of paces needed to reach both points?
A scribe is recording the differences in weight between two statues, one weighing CXVII kilograms and the other LXXXIV kilograms. What is the difference in weight?
Convert the sum of 56 and 67 into Roman numerals using the expansion method.
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.