Unit Plan - Mathematics - Integer Arithmetic

The aim of this unit plan is to introduce students to the addition, subtraction, multiplication and division of integers, where negative integers are involved.

The goal is that students become proficient in the following:

• adding and subtracting integers using models;
• adding and subtracting integers using paper and pencil;
• multiplying and dividing integers using paper and pencil.

The plan consists of 4 lessons, which can be taught in 4-6 lesson-hours.

First, students are presented with a counter model of the addition of integers. The patterns they observe are used to present the most important, and basic, rules of addition of integers, including:
“adding integer -b is the same as subtracting its ‘opposite’ b”.
The rules are presents both in words and symbolically.

Students are then presented with a counter model of the subtraction of integers. The patterns they observe are use to present the basic rules of subtracting of integers, especially:
“subtracting integer -b is the same as adding its ‘opposite’ b”.

Finally, students are introduced to the rules for products and quotients of integers. The connection between the latter rules and those for addition are highlighted.