Adding Integers

Integers: Positive + Positive

To add Integers, we will use a number line. The number line will help us organize our information and provide a positional strategy for dealing with numbers of this type. Here is the strategy.

When you add two positive numbers, locate the first number on the number line. Next, move to the right of that number a number of spaces equal to the second number. The answer to the problem is the same value as the last number on which you land.

Let us examine two examples that use this positional strategy. The number line below will assist you through the process.

Example #1: 1 + 3
Even though this problem is simple by most people's standards, getting used to the number line as it applies to adding Integers will help you deal with harder problems. The strategy says that you must start on the number line at 1. Next, the strategy says that you must move 3 spaces to the right. If you move to the right 3 spaces, you should go from 1 to 2, from 2 to 3, and from 3 to 4, for a total of 3 spaces. The last position is 4 and that is the answer to the problem. Therefore, 1 + 3 = 4.
Example #2: 2 + 7
Following the same procedure as example 1 above, start at 2. Next, move 7 spaces to the right. Our number line is too short to complete the problem, so extend it to the right about 10 spaces. After moving 7 spaces, the final position should be 9. Therefore, 2 + 7 = 9.

To help you learn other skills with Integers, use the links below.

Positive + Negative
Negative + Positive
Negative + Negative

Go to Subtracting Integers.
Go to the Frontpage.
Go to MATHguide.

(Updated October 17th, 2004)