# Letters or Numbers?

## Overview

Students will learn to identify, count, and write Roman numerals.  Using the reverse of the 3-cent nickel as a starting point, students will be able to recognize Roman numerals and distinguish them from letters.

## Activity

After reading the July 2008 Coin of the Month, display and discuss the reverse image of the 3-cent nickel.  Ask the students if they believe the reverse features numbers, letters, or both.  Explain to the students that the numbers they are familiar with originated in Arabia and are called Arabic numerals.  The numbers on the reverse of the 3-cent nickel are called Roman numerals, a numeric system that was used in ancient Rome.

On the board or a piece of chart paper write down the six basic symbols used in the Roman numeral system:  I (one), V (five), X (ten), L (fifty), C (one hundred), and M (one thousand).  Explain to the students that there are two basic rules when writing Roman numerals:

1. Writing a numeral of lesser value before a numeral of greater value decreases the second numeral by the amount of the first.  Example:  IV equals four because V (five) is decreased by I (one).
2. Writing a numeral of lesser value after a numeral of greater value increases the first numeral by the amount of the second.  Example:  VI equals six because V (five) is increased by I (one).

Write the numbers 1 through 10 on the board or chart paper.  Have the students translate the Arabic numerals into Roman numerals.  As a class, translate other numeric items into Roman numerals such as the numbers on the clock, the year, or a basic math problem.  Have students create their own chart by writing different numbers and translating them into Roman numerals.  Display student charts around the room.

## Extension

Have students locate examples of different numeric systems from around the world using books, magazines and/or newspapers, or the Internet with adult supervision.  Have a class show-and-tell day where students are able to share their examples with the class.  Create a display area where students can contribute their examples of numeric systems.

## Standards

The project described above reflects some of the national standards of learning as defined by the National Council for the Social Studies (NCSS) and the National Council of Teachers of Mathematics (NCTM).  These standards are listed below:

### Social Studies Standards

Culture:  Students will identify the origins of the Arabic and Roman Numeral Systems.

### Mathematics Standards

Number and Operations:  Students will use quick recall of addition facts and related subtraction facts to complete Roman numeral conversions.