Warm Up (8) 2. 6(12) (7)6. Multiply or Divide

Section 1.6 Multiplying & Dividing Integers

Objectives NS1.2 Add, subtract, multiply, and divide rational numbers (integers, fractions, and terminating decimals) and take positive rational numbers to whole-number powers. California Standards

Multiplying & Dividing Two Integers 1. Same signs = positive 2. Different signs = negative 2 Simple Rules

Examples 4(3) 5(-2) (-4)(-6) (-3)² Both signs are positive so answer is positive = 12 Different signs, so answer will be negative-- = -10 Same signs, so answer will be positive = times -3, so same signs mean positive answer = 9

Simplifying Expressions Using Multiplication -8 (-y) = ● 10 (-a) ● (-11)(-w) Remember: the dot and parentheses next to a number or letter means to multiply. 8y Because a negative times a negative equals a positive, your answer is positive -10a11w Here, negative times a positive equals a negative

Let’s practice… A. –6(4) B. –8(–5)(2) 40(2) –24 Multiply or divide. –8(–5)(2) 80 C. –9 –18 2 D. 5 –25 –5

Let’s practice… A. 3(–6 – 12) –54 3(–18) B. –5(–5 + 2) 15 –5(–3) 3(–6 + –12)

Sports Application A golfer plays 5 holes. On 3 holes, he is 4 strokes over par. On 2 holes, he is 4 strokes under par. Each score over par can be represented by a positive integer, and each score under par can be represented by a negative integer. Find the total score relative to par. 3(4) + 2(–4) (–8) The golfer's score was 4 over par.

Check It Out! A. -3(-2)(4) 24 B. -3(6)

Sports Application 3(3) + 4(–3) –3 9 + (–12) A golfer plays 7 holes. On 3 holes, he has a gain of 3 strokes. On 4 holes, he is 3 strokes under par. Each score over par can be represented by a positive integer, and each score under par can be represented by a negative integer. Find the total score relative to par. The golfer's score was 3 under par.

try these! 4 ( -6) ● -5(2) = -24 = = -6= -8=1 x = 5 y = -8 9x -5 x²yx²y -yx 9(5) ²(-8) 25(-8) (-8)5 40

Lesson Quiz 1. –8(4)2. –32 6 –12(5) –10 3. –2(13 – 4) 4. 6(–5 – 3)–18–48 5. Devin completes 11 transactions in his bank account. In 6 transactions, he withdraws $10. In 5 transactions, he deposits $20. Find the total net change in dollars. $40

SUMMARY Rules for multiplying and dividing integers….