1. MULTIPLYING RATIONAL NUMBERS
LESSON 8

2. Multiplying Integers Positive x Positive = Positive
Positive x Negative = Negative
Negative x Negative = Positive
Negative x Positive = Negative
An odd number of Negatives multiplied together gives a negative result.
An even number of Negatives multiplied together gives a positive result.

3. EXAMPLES: Positive x Positve Positve x Negative Negative x Negative
= + 40
Positive x Positve
(+7) x (-6)
= - 42
Positve x Negative
(-4) x (-3)
= + 12
Negative x Negative
(-8) x (+9)
= - 72
Negative x Positive
(-4) x (-2) x (-3)
= - 24
Odd number of Negatives
(-1) x (-9) x (-3) x (-2)
= + 54
Even number of Negatives

4. Multiplying Rational Numbers
1) Use the SAME RULES for Rational numbers as you did for Integers.
2) Same rules as you did for Fractions  multiply the two numerators and the two denominators.
REMEMBER: If there are negative signs to place them in the numerator.

5. EXAMPLES 3 5 3 5 9 25 x = 2 5 -3 4 -6 20 x = -4 7 -3 8 12 56 x =
NEGATIVE x NEGATIVE = POSITIVE

6. MORE EXAMPLES -4 -5 -3 6 x = 2 5 -3 4 2 x = -2 3 -3 4 -3 -2 x x =

7. MORE EXAMPLES -12 30 -4 -5 -3 6 2 5 -3 4 -2 3 -3 4 -3 -2 2 x = x = x x

8. MORE EXAMPLES -4 -5 -3 6 -12 30 -2 5 2 5 -3 4 -2 3 -3 4 -3 -2 2 = x =
ODD Number of Negatives = Negative = x =
Reduced to LOWEST TERMS 2 5 -3 4 2 x = -2 3 -3 4 -3 -2 x x =

9. MORE EXAMPLES -2 5 -4 -5 -3 6 2 5 -3 4 12 5 -3 4 -2 3 -3 4 -3 -2 2 x =
CHANGE MIXED TO AN IMPROPER FRACTION 2 5 -3 4 12 5 -3 4 2 x = x = -2 3 -3 4 -3 -2 x x =

10. MORE EXAMPLES -2 5 -4 -5 -3 6 2 5 -3 4 12 5 -3 4 -36 20 -2 3 -3 4 -3= 2 5 -3 4 12 5 -3 4
-36 20 2 x = x = = -2 3 -3 4 -3 -2 x x =

11. MORE EXAMPLES -2 5 -4 -5 -3 6 2 5 -3 4 12 5 -3 4 -36 20 4 5 -2 3 -3 4=
Change back to mixed and reduce fraction 2 5 -3 4 12 5 -3 4
-36 20 4 5 2 -1 x = x = =
Positive x Negative = Negative -2 3 -3 4 -3 -2 x x =

12. MORE EXAMPLES -2 5 -4 -5 -3 6 2 5 -3 4 4 5 -2 3 -3 4 -3 -2 18 24 2 -1= 2 5 -3 4 4 5 2 -1 x = -2 3 -3 4 -3 -2 18 24 x x =

13. MORE EXAMPLES -2 5 -4 -5 -3 6 2 5 -3 4 4 5 -2 3 -3 4 -3 -2 18 24 3 4 2= 2 5 -3 4 4 5 2 -1 x =
Reduce to LOWEST TERMS -2 3 -3 4 -3 -2 18 24 3 4 x x = =
EVEN Number of Negatives = Positive

14. YOU TRY! -4 5 3 7 = x -5 8 3 -7 -2 -4 x x = 1 6 3 7 -1 x =