Multiplying and Dividing Integers Rules for Multiplying Integers

Multiplying and Dividing Integers

Rules for Multiplying Integers 1. Multiply the numbers 2. Same signs, answer is positive. 3. Different signs, answer is negative.

Rules for Dividing Integers 1. Divide the numbers 2. Same signs, answer is positive. 3. Different signs, answer is negative.

Examples with Multiplication 1. 5 × 4 = 2. 5 × -4 = 3. -5 × -4 = 4. -5 × 4 = 20 (Same signs, answer is positive) -20 20 -20 (Different signs, answer is negative) (Same signs, answer is positive) (Different signs, answer is negative)

Examples with Division 1. 21 ÷ 3 = 7 (Same signs, answer is positive) 2. 21 ÷ -3 = -7 3. -21 ÷ -3 = 7 4. -21 ÷ 3 = -7 (Different signs, answer is negative) (Same signs, answer is positive) (Different signs, answer is negative)

Practice Problems 1. -50 ÷ -5 = 2. -9 × 4 = 10 -36 6. 7 × -6 = -42 7. -48 ÷ -8 = 6 3. 60 ÷ -12 = -5 8. -11 × 6 = -66 4. -8 × -7 = 56 9. 72 ÷ -9 = -8 5. -100 ÷ 10 = -10 10. -15 × -2 = 30

Word Problems 1. The temperature is currently at 10°Fahrenheit. The temperature decreases 7 degrees every hour. If 2 hours pass, what is the new temperature? 7 × 2 = 14 so it decreases 14⁰F 10 – 14 = -4⁰F 2. Jane has $125 in her bank account. Her cell phone bill is $47 a month. If she pays that bill two months in a row and doesn’t buy anything else or deposit any money, how much money does she have left? 47 × 2 = $94 to pay the bills $125 - $94 = $31 left