Lesson: Roman Numerals
Roman numerals are a number system that was used in ancient Rome, and we still use them today in some places, like clocks and book chapters. Let’s learn the basics and how to work with Roman numerals!
Basic Roman Numerals
The Roman numeral system uses letters to represent numbers. Here are the most important ones to know:
- I = 1
- V = 5
- X = 10
- L = 50
- C = 100
- D = 500
- M = 1,000
Roman Numerals 1-9
Here’s how to represent the numbers 1 through 9 using Roman numerals:
- I = 1
- II = 2
- III = 3
- IV = 4 (5 – 1)
- V = 5
- VI = 6 (5 + 1)
- VII = 7 (5 + 2)
- VIII = 8 (5 + 3)
- IX = 9 (10 – 1)
Matching Roman Numerals
When matching Roman numerals with their regular numbers, it’s helpful to remember the basic symbols. For example:
- II matches 2
- V matches 5
- IX matches 9
Addition and Subtraction with Roman Numerals
When using Roman numerals in math, the placement of the symbols matters. Here’s how addition and subtraction work:
- Addition: When smaller numbers are added after larger ones, you add them.
- Example: VI = 5 + 1 = 6
- Subtraction: When smaller numbers come before larger ones, you subtract.
- Example: IV = 5 – 1 = 4
Comparing Roman Numerals
When comparing Roman numerals, the larger the letters, the larger the number. For example:
- VI (6) is larger than IV (4).
- IX (9) is larger than VIII (8).