### Purpose

Increase students' knowledge of the geographic and historical context in which place value
numeration was introduced in West Europe.

### Objectives

Students will be able to:

- recognize a map of the Mediterranean and locate Algeria, Egypt, Greece, Italy, North Africa, Pisa, Sicily,
Syria;
- add and subtract using an abacus;
- read and write Roman numerals;
- relate the simplicity of addition and subtraction rules to the idea of place value.

### Activities

- Provide students with blank maps of the Mediterranean and have them label locations.
- Add and subtract with a simple 4 wire abacus.
- Add and subtract some Roman numerals and compare to place value computation.
- Explain why adding digits gives the sum and subtracting digits gives the difference of numbers in base ten.
Explain how "carrying" works in addition and "borrowing" works in subtraction.