3 6 Multiplying Integers Standard Number Sense Indicator

3 -6 Multiplying Integers Standard: Number Sense Indicator (s): N 6 Simplify numerical expressions involving integers and use integers to solve real-life problems. N 8 Develop and analyze algorithms for computing with integers and demonstrate fluency in their use.

Examples 1. -5∙ 3 ← 3 groups of negative 5 -15 2. 10 ∙ (-4) ← 10 groups of negative 4 3. -40 2∙ 4∙(-8) 8(-8) ← 8 groups of -8 -64

1. Jenny is running a lemonade stand. She is losing $2 a day. If she is at $ 0 today. Complete the table 5 days 2 days 1 day ago ago (-5) (-2) (-1) Today In 1 day (0) (1) In two In 5 days (5) (2) -2(-5) -2(0) -2(2) -2(-1) -2(1) (-2)5 ** If you have a negative amount, a negative number of times it is actually a. . Positive

Rules for Multiplying Integers Count the number of negative signs o If there an even number of negatives the answer is - Positive Example (-2)(-3)(-4)(-1) ← 4 negatives (6)(4) 24 ← positive answer Example (-3)2 (-3) 9

n If there an odd number of negatives the answer is - negative Example (-2)(3)(-4)(-1)← 3 negatives (-6)(4) -24 ← negative answer Example -(4)3 -(4)(4)(4) -64 Example (-2 x)(8 y) -16 xy

You Try o -4 x(-3 y) o -5(6)(-2)(7) o - 62 o (-6)2

Assignments o Period 6, 7 o 3 -6 o Pg. 136 -137 o # 24 -43, 45 -48, 52, 58 -60 o Period 1, 3, 8 o 3 -6 o Pg. 136 -137 o #14 -42 e, 46, 47, 50 -60