# Integers

Signed Numbers

Signed numbers, also called integers, are numbers that show not only how far a number is from zero on a number line, but which side of zero it is on. A number that is 3 less than zero is -3 and a number that is 3 more than zero is 3.

If you have two numbers that are the same sign being added together, you add them and keep the sign the same. 3 + 5 = 8. Also, -3 + -5 = -8. If the signs are different, subtract and keep the sign of the larger (further from zero) number. -3 + 5 = 2; and 3 + -5 = -2. Also any number following a subtraction sign is negative, so 3 + -5 is the same thing as saying 3 – 5.

Multiplying and Dividing Integers

When multiplying or dividing integers, you multiply or divide as you normally would, then follow this rule for determining the sign: If the signs are the same, the answer is positive. If the signs are different, the answer is negative. Therefore: 3 • 5 = 15 3 • -5 = -15 -3 • 5 = -15 -3 • -5 = 15

Absolute Value

Absolute value is a measure of how far a number is from zero on a number line regardless of which side of zero it is on. We show absolute value by putting these lines around a number: |3|. The absolute value of a number is always positive, so |3| = 3 and |-3| = 3.