http://www.greenemath.com/

In this lesson, we will learn how to add two or more integers together. We will start with a general understanding of the concept by adding integers on a number line. We will see that adding two integers with the same sign is done by adding the absolute values and then attaching the common sign. When we add two integers with a different sign, we subtract the larger absolute value minus the smaller, and then attach the sign of the number with the larger absolute value.

0:00 Introduction
0:22 Procedure to Add on a Number Line
1:50 Adding Integers with the Same Sign on the Number Line
7:19 Procedure for Adding Integers with the Same Sign
7:31 Adding Integers with the Same Sign without a Number Line
8:54 Adding Integers with Different Signs on the Number Line
16:27 Adding Integers with Differenct Signs without a Number Line
19:42 Adding more than two Integers with Mixed Signs