Roman Numerals Chapter Notes | Mathematics Class 4 ICSE PDF Download

Introduction

Dive into the fascinating world of Roman numerals, a number system created by the ancient Romans thousands of years ago! Unlike the numbers we use today, Roman numerals use special letters from the alphabet to represent values. This chapter will take you on a journey to understand these unique symbols, how to read them, and how to write them. Get ready to explore a system that’s still used on clocks, in books, and even in movies, bringing a touch of history to our modern world!

Symbols of Roman Numerals

• Roman numerals use seven letters as symbols: I, V, X, L, C, D, and M.
• Each symbol represents a specific value in the Hindu-Arabic numeral system.
• There is no symbol for zero in the Roman numeral system.
• The values are:
  • I = 1
  • V = 5
  • X = 10
  • L = 50
  • C = 100
  • D = 500
  • M = 1000
• Example: The symbol X represents the number 10.

Reading Roman Numerals

• Roman numerals are written by combining the seven symbols to form numbers.
• Numbers are created by adding or subtracting the values of these symbols based on specific rules.
• Example: XV = 10 + 5 = 15

Rule 1

• When a symbol is repeated, add its value each time to get the total.
• A symbol can only be repeated up to three times.
• Example: III = 1 + 1 + 1 = 3

Rule 2

• When a smaller symbol comes after a larger symbol, add their values together.
• Example: VIII = 5 + 1 + 1 + 1 = 8

Rule 3

• When a smaller symbol comes before a larger symbol, subtract the smaller value from the larger one.
• Example: IV = 5 - 1 = 4

Rule 4

• When a smaller symbol is between two larger symbols, subtract the smaller symbol’s value from the larger symbol that comes after it, then add the result to the first larger symbol.
• Example: XIV = 10 + (5 - 1) = 10 + 4 = 14

​Roman Numerals up to 39

Solved Examples