In this lesson you will learn about adding and subtracting integers. Integers are positive and negative whole numbers and when first learning about integers it is useful to visualize how one integer is related to the other.
This is when we use a number line. A number line is a line that has the origin, 0, to the right of which there are positive numbers and to the left of which there are negative numbers. We can move along the number line and determine the position of any integer. We have previously used it to compare integers.
You will discover the concept of the absolute value and why it is important when performing operations with integers. It is also useful when solving certain types of equations and later, when analyzing absolute value functions and their graphs.
On a number line, the distance between the two numbers is given as an absolute value.
For example, the distance from -10 to +10 is 20. However, if we add -10 and +10 the answer is 0 – they are the exact opposites. If we were to subtract +10 from -10, it would be recorded as -10 – (+10) and would equal -20 ( because on a number line a positive direction has changed to a negative direction).
Check out the video lesson above for more explanation on this concept.