1. multiply rational numbers. SOL: none Objectives The student will be able to: Designed by Skip Tyler, Varina High School and Nicole Kessinger Deep Run High School

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

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

3) = =

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?

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