1. Objective 3 Multiplying and Dividing Integers © 2000 by R. Villar All Rights Reserved

2. Multiplying /Dividing Integers Ex. –3 + (–3) + (–3) + (–3) = –12 This is the same as 4 (–3) = –12 You can see that a positive times a negative integer gives a negative product. + – = – – + = – – – = + + + = +

3. Ex. a. 5(–11) – 55 What about 5(–11)(2) ? = –55 2 = –110 Rule for multiplication: An odd amount of negatives gives a negative product. An even amount of negatives gives a positive product.

4. Division of Real Numbers The product of a number and its reciprocal is 1. Here are some examples of reciprocals: 1/4 and 4 –5/2 and –2/5 –9 and –1/9 To divide a number, you can multiply by its reciprocal. b ÷ a = b 1/a So the rules for dividing real numbers are the same as multiplying real numbers. + ÷ – = – – ÷ + = – – ÷ – = + + ÷ + = +

5. Example:–24 ÷ (–3) negative ÷ negative = positive 8 Example: 28 –4 –7