1. Multiply and rational numbers Objective The student will be able to:

2. Multiplying Rules 1) If the numbers have the same signs then the product is positive. (-7) (-4) = 28 2) If the numbers have different signs then the product is negative. (-7) 4 = -28

3. Examples 1) (3x)(-8y) 2) Write both numbers as a fraction. Cross-cancel if possible. =-16 Multiplying fractions: top # Bottom # bottom# -24xy

4. When multiplying two negative numbers, the product is negative. 1.True 2.False Answer Now

5. When multiplying a negative number and a positive number, use the sign of the larger number. 1.True 2.False Answer Now

6. 3) = =

7. Multiply: (-3)(4)(-2)(-3) 1.72 2.-72 3.36 4.-36 Answer Now

8. an easy way to determine the sign of the answer 3 negative signs -> Odd -> answer is negative -480 When you have an odd number of negatives, the answer is negative. When you have an even number of negatives, the answer is positive. 4) (-2)(-8)(3)(-10) Do you have an even or odd number of negative signs?

9. Last one! 5) Positive or negative answer? Positive - even # of negative signs (4) Write all numbers as fractions and multiply. =12

10. What is the sign of the product of (-3)(-4)(-5)(0)(-1)(-6)(-91)? 1.Positive 2.Negative 3.Zero 4.Huh? Answer Now

11. Dividing Rules 1) If the numbers have the same signs then the quotient is positive. -32 ÷ (-8 )= 4 2) If the numbers have different signs then the quotient is negative. 81 ÷ (-9) = -9

12. When dividing two negative numbers, the quotient is positive. 1.True 2.False Answer Now

13. When dividing a negative number and a positive number, use the sign of the larger number. 1.True 2.False Answer Now

14. The reciprocal of is where a and b  0. The reciprocal of a number is called its multiplicative inverse. A number multiplied by its reciprocal/multiplicative inverse is ALWAYS equal to 1.

15. Example #1The reciprocal of is Example #2 The reciprocal of -3 is

16. Basically, you are flipping the fraction! We will use the multiplicative inverses for dividing fractions.

17. Which statement is false about reciprocals? 1.Reciprocals are also called additive inverses 2.A number and its reciprocal have same signs 3.If you flip a number, you get the reciprocal 4.The product of a number and its reciprocal is 1 Answer Now

18. When dividing fractions, change division to multiplying by the reciprocal. Examples 1)

19. 2)

20. What is the quotient of -21 ÷ -3? 1.18 2.-18 3.7 4.-7 Answer Now

21. 1.. 2.. 3.. 4..