Lesson: Introduction to Roman Numerals
Beginner lesson for learning I–X and basic conversion.
Difficulty: Beginner · Classroom support material (not claimed as aligned to a specific state standard)
Objective
Students will recognize the seven Roman numeral symbols and convert numbers 1–20 in both directions.
What students need to know
- Arabic numbers 1–20
- The idea that letters can stand for values
Explanation
Roman numerals use seven letters: I V X L C D M. Beginners start with I (1), V (5), and X (10). Values are usually added left to right, and four and nine use the subtractive pairs IV and IX.
Examples
- 3 = III
- 4 = IV (not IIII in modern classroom form)
- 9 = IX
- 14 = XIV
- 20 = XX
Short guided practice
- Write 1–10 as Roman numerals together as a class.
- Have students convert five Arabic numbers to Roman and five Roman numerals back to Arabic.