Integers are defined as the group of positive numbers, negative numbers, and zero.
Negative numbers are always shown with a minus (-) sign. Positive numbers do not need to have a + sign. Remember integers are represented by small slashes on the number lines, and do not include the fractional or decimal numbers in between the slashes.
When adding and subtracting integers, it is helpful to use a number line! Use the following rules to remember how it is done!
When adding integers, think number line!
In the example -5 + 3 = , start on the number line at -5 and since 3 is positive, move to the right 3 spaces!
(-5) + 3 = (-2)
Let's try one with
a negative second number.
(-4) + (-2) = (-6)
Remember, subtraction and addition are just opposite operations. So to subtract integers, just add the opposite of the second number.
First let's review "opposites"! An opposite of a number is the same distance from zero. Soooo, (-8) is an opposite number from +8 (or 8), and 5 is the opposite of (-5).
So when subtracting integers, simply add the opposite of the second number!
Let's do some examples:
6 - 4 =
6 + (-4) = 2
One more example! (Subtracting a negative is like adding a positive).
(-4) - (-2) =
(-4) + 2 = (-2)