multiplying and dividing integers 1-7 warm up warm up lesson presentation lesson presentation...
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Multiplying and Dividing Integers1-7
Warm UpWarm Up
Lesson PresentationLesson Presentation
Problem of the DayProblem of the Day
Lesson QuizzesLesson Quizzes
Multiplying and Dividing Integers1-7
Warm UpMultiply or divide.
40 72
7
12
4
126
1. 5(8) 2. 6(12)
3.36
94.
49
7
192
165. 18(7) 6.
Multiplying and Dividing Integers1-7
Problem of the Day
Complete the pyramid by filling in the missing numbers. Each number is the sum of the numbers in the two boxes below it.
8–9
–7 –1 5
–4
–8
–32
4
Multiplying and Dividing Integers1-7
Learn to multiply and divide integers.
Multiplying and Dividing Integers1-7
A positive number multiplied by an integer can be written as repeated addition.
3(–200) = –200 + (–200) + (–200) = –600
From what you know about adding and subtracting integers, you can see that a positive integer times a negative integer is negative.
Multiplying and Dividing Integers1-7
You know that multiplying two positive integers together gives you a positive answer. Look for a pattern in the integer multiplication at right to understand the rules for multiplying two negative integers.
3(–200) =
2(–200) =
1(–200) =
0(–200) =
–1(–200) =
–2(–200) =
–3(–200) =
–600
–400+ 200
–200
0
200
400
600
+ 200
+ 200
The product of two negative integers is a positive integer.
Multiplying and Dividing Integers1-7
Multiplying and Dividing Integers1-7
Additional Example 1: Multiplying and Dividing Integers
A. –6(4)
B. –8(–5)
40
–24
Signs are different.
Signs are the same.
Answer is negative.
Answer is positive.
Multiply or divide.
Multiplying and Dividing Integers1-7
Additional Example 1: Multiplying and Dividing Integers
C.
–9
Signs are different.
Answer is negative.
Multiply or divide.
–182
D.
5
Signs are the same.
Answer is positive.
–25–5
Multiplying and Dividing Integers1-7
Check It Out: Example 1
A. 5(–2)
B. –3(–2)
6
–10
Signs are different.
Signs are the same.
Answer is negative.
Answer is positive.
Multiply or divide.
Multiplying and Dividing Integers1-7
Check It Out: Example 1
C.
–8
Signs are different.
Answer is negative.
Multiply or divide.
–243
D.
6
Signs are the same.
Answer is positive.
–12–2
Multiplying and Dividing Integers1-7
Additional Example 2: Using the Order of Operations with Integers
A. 3(–6 – 12)
–54
3(–18)Subtract inside the parentheses.
Think: The signs are different.
The answer is negative.
Simplify.
B. –5(–5 + 2)
15
–5(–3)Subtract inside the parentheses.
Think: The signs are the same.
The answer is positive.
Multiplying and Dividing Integers1-7
Additional Example 2: Using the Order of Operations with Integers
C. –2(14 – 5)
–18
–2(9)Subtract inside the parentheses.
Think: The signs are different.
The answer is negative.
Simplify.
Multiplying and Dividing Integers1-7
Check It Out: Example 2
A. 2(1 – 8)
–14
2(–7)Subtract inside the parentheses.
Think: The signs are different.
The answer is negative.
Simplify.
B. 4(–3 – 8)
–44
4(–11)Subtract inside the parentheses.
Think: The signs are different.
The answer is negative.
Multiplying and Dividing Integers1-7
Check It Out: Example 2
C. –3(6 – 9)
9
–3(–3)Subtract inside the parentheses.
Think: The signs are the same.
The answer is positive.
Simplify.
Multiplying and Dividing Integers1-7
Additional Example 3: Sports Application
A golfer plays 5 holes. On 3 holes, he is 4 strokes over par. On 2 holes, he is 1 stroke 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(–1)
10
12 + (–2)
Add the losses to the gains.
Multiply.
Add.
The total score is 10 strokes over par.
Multiplying and Dividing Integers1-7
Check It Out: Example 3
A golfer plays 9 holes. On 3 holes, he is 3 strokes over par. On 4 holes, he is 3 stroke 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(3) + 4(–3)
–3
9 + (–12)
Add the losses to the gains.
Multiply.
Add.
The total score is 3 strokes under par.
Multiplying and Dividing Integers1-7
Standard Lesson Quiz
Lesson Quizzes
Lesson Quiz for Student Response Systems
Multiplying and Dividing Integers1-7Lesson Quiz
Multiply or divide.
1. –8(4) 2.–32 6–12(5)–10
Simplify.
3. –2(13 – 4) 4. 6(–5 – 3)–18 –48
5. Evin 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
Multiplying and Dividing Integers1-7
1. Multiply –9(6).
A. 54
B. 45
C. –45
D. –54
Lesson Quiz for Student Response Systems
Multiplying and Dividing Integers1-7
2. Multiply or divide .
A. –19
B. 19
C. 30
D. 36
Lesson Quiz for Student Response Systems
–19(4) –4
Multiplying and Dividing Integers1-7
3. Simplify –7(17 – 6).
A. –77
B. –66
C. 66
D. 77
Lesson Quiz for Student Response Systems
Multiplying and Dividing Integers1-7
4. Simplify 9(–6 – 1).
A. 63
B. 54
C. –63
D. –64
Lesson Quiz for Student Response Systems
Multiplying and Dividing Integers1-7
5. Hannah makes 14 trips to her mom’s home. On 8 of her trips, she gives her mom $25 for safekeeping. On her other 6 trips, she takes $30 from her mom. How much of Hannah’s money is left with her mom?
A. $10
B. $20
C. $30
D. $40
Lesson Quiz for Student Response Systems