Negative Numbers and Integers

What this chapter covers

• Why we need negative numbers
• Integers
• Representing integers on the number line
• Comparing and ordering integers
• Addition and subtraction of integers

Key definitions

Key points

• Negative numbers are numbers less than zero, written with a minus sign, such as -4.
• Positive and negative numbers describe opposite situations: gain and loss, above and below, up and down.
• Zero is the reference point and is neither positive nor negative.
• Integers are the numbers ldots, -3, -2, -1, 0, 1, 2, 3, ldots and they go on without end in both directions.
• Every integer has an opposite at the same distance from zero; an integer plus its opposite is zero.
• On a number line, positive integers lie to the right of zero and negative integers to the left.
• Of two integers, the one farther to the right on the number line is greater.
• Every negative integer is less than zero and less than every positive integer.
• To add a positive integer, move right; to add a negative integer, move left.
• To subtract an integer, add its opposite.

Questions answered