For use with pages xxx–xxx9/12/12 Warm-Up

1. + =6.217.3 ?–

2. =26.9 – ( )5.8– ?

ANSWER 32.7

ANSWER 11.1–

3. A climber is 10400 ft above sea level. He descends 500 ft to a fellow climber. What is his new height above sea level?

–

ANSWER 9900 ft

4. Find

1721– –

5.

ANSWER 38–

ANSWER 11.8

ALGEBRA GAME PLANDate 9/9/13 MondaySection 1-6: Multiplying and Dividing Real Numbers

Objective

Students will be able to multiply and divide real numbers.

Algebra California StandardHomework

P 41 - 44, #1-12 (choose 5), 32 – 39 (choose 3),

Announcement

Quiz, Wednesday 9/11

ALGEBRA 1

The Rules of Multiplying and Dividing Real Numbers• Two numbers that are multiplied or divided with

the SAME SIGN give a POSITIVE answer+ + = + - - = ++ + = + - - = +

• Two numbers that are multiplied or divided with DIFFERENT SIGNS give a NEGATIVE answer+ - = - - + = -+ - = - - + = -

ALGEBRA 1

Math Dog(Multiply or Divide)

ALGEBRA 1

Math Dog(Multiply or Divide)

-4 9

-4-4

+9+9

-36-36

the answer is negative

ALGEBRA 1

Math Dog(Multiply or Divide)

-24 -3

-24-24 -3-3

88

the answer is positive

ALGEBRA 1

Simplify each expression.

a. –3(–11) –3(–11) = 33 The product of two negative numbers is positive.

b. –6( )34

The product of a positive number and a negative number is negative.

–6( ) = –34

184

Multiplying and Dividing Real NumbersLESSON 1-6

Additional Examples

= _ 9 2

ALGEBRA 1

Multiplying and Dividing Real NumbersLESSON 1-6

Additional Examples Practice

Simplify each expression. (choose 4)

1) -8(3)2) 4(-4)3) -20(-6 + 2)4) -7(-1.2)5) -11(⅛)6) 15(-⅗)7) | (-12)2 |8) | (-10)(-5) |

Answers

1) -242) -163) 804) 8.45) -11/86) -97) 248) 50

ALGEBRA 1

Properties of Multiplication

ALGEBRA 1

Which property is this?

10(0) = 0

Multiplication Property of Zero

ALGEBRA 1

Which property is this?

-1(8) = -8

Multiplication Property of Negative One

ALGEBRA 1

Which property is this?

23(1) = 23

Identity Property of Multiplication

ALGEBRA 1

Use the order of operations to simplify each expression.

a. –0.24

= –0.0016 Simplify.

= 0.0016 Simplify.

b. (–0.2)4

Write as repeated multiplication.–(0.2 • 0.2 • 0.2 • 0.2)=

Write as repeated multiplication.(–0.2)(–0.2)(–0.2)(–0.2)=

Multiplying and Dividing Real NumbersLESSON 1-6

Additional Examples

I DO

WE DO

ALGEBRA 1

Use the order of operations to simplify each expression.

a. (–0.3)3

= –0.027

= -0.027

b. –0.33

(–0.3)(–0.3)(–0.3)

=

Multiplying and Dividing Real NumbersLESSON 1-6

Additional Examples

YOU DO TOGETHER

–(0.3 • 0.3 • 0.3)

ALGEBRA 1

Simplify each expression.

a. 100 ÷ (–5)

b. –54 ÷ (–9)

The quotient of a positive number and a negative number is negative.= –20

The quotient of a negative number and a negative number is positive.= 6

Multiplying and Dividing Real NumbersLESSON 1-6

Additional Examples

ALGEBRA 1

Multiplying and Dividing Real NumbersLESSON 1-6

Additional Examples Practice

Simplify each expression. (choose 3)

1) -24 ÷(- 4)

2) 36 ÷ (-3)

3) -16 ÷ (-6 + 2)

4) -1÷ (0.2)

5) - 23 ÷ (3)

6) 15 ÷ (8 – 11)

Answers

1) 6

2) -12

3) 4

4) -5

5) -23/3 or -7⅔

6) -5

ALGEBRA 1

One More Property

A number’s multiplicative inverse is the

of that number.RECIPROCALRECIPROCAL

ALGEBRA 1

Find the Multiplicative Inverse

1. ⅘2. -73. ⅚4. -⅓

1. 5/4

2. -1/7

3. 6/5

4. -3

ALGEBRA 1

Ticket out the door (TOD)

Given: a = -5, b = -2, m = -3, and p = -1

Evaluate

1) 6ab

1) (mp)3

2) a + m

bp

ALGEBRA 1

9/13/12 Warm Up

Simplify1. -13(4)2. -8(-9 + 2)3. 72 ÷ (-12)

4. -102 ÷ (-2)

5. (2 – 3)(7)(-6 + 9)

6. What is another word for multiplicative inverse?

Answers1. -522. 563. -64. 505. -216. .reciprocal

ALGEBRA GAME PLANDate 9/10/13 TuesdaySection 1-6: Multiplying and Dividing Real Numbers

Objective

Students will be able to multiply and divide real numbers.

Algebra California Standard

Homework

P 41 – 44: Choose 2 from each set(18-24), (25-30), (48-53)Everyone must do 54, 61, 97, 98

Announcement

Quiz, Wednesday 9/11

ALGEBRA 1

Evaluate 5rs for r = –18 and s = –5.

5rs = 5(–18)(–5) Substitute –18 for r and –5 for s.

= –90(–5) 5(–18) results in a negative number, –90.

= 450 –90(–5) results in a positive number, 450.

Multiplying and Dividing Real NumbersLESSON 1-6

Additional Examples

ALGEBRA 1

Evaluate -3ab for a = –7 and s = 9.

5rs = 5(–18)(–5) Substitute –18 for r and –5 for s.

= –90(–5) 5(–18) results in a negative number, –90.

= 450 –90(–5) results in a positive number, 450.

Multiplying and Dividing Real NumbersLESSON 1-6

Additional Examples

ALGEBRA 1

Practice

ALGEBRA 1

Use the expression –5.5( ) to calculate the

change in temperature for an increase in altitude a of 7200 ft.

a 1000

–5.5( ) = –5.5 ( )72001000

a 1000

Substitute 7200 for a.

= –5.5(7.2) Divide within parentheses.

= –39.6°F Multiply.

The change in temperature is –39.6°F.

Multiplying and Dividing Real NumbersLESSON 1-6

Additional Examples

ALGEBRA 1

Evaluate – – 4z2 for x = 4, y = –2, and z = –4.

= – 4(16) Simplify the power.–4–2

= 2 – 64 Divide and multiply.

= –62 Subtract.

xy

– – 4z2 = – 4(–4)2 Substitute 4 for x, –2 for y, and –4 for z.xy

–4–2

Multiplying and Dividing Real NumbersLESSON 1-6

Additional Examples

ALGEBRA 1

Evaluate for p = and r = – .

= –2 Simplify.

pr

32

34

= p ÷ r Rewrite the equation.pr

= ÷ Substitute for p and – for r.34

(– )32

32

34

= Multiply by – , the reciprocal of – .43

(– )32

43

34

Multiplying and Dividing Real NumbersLESSON 1-6

Additional Examples

ALGEBRA 1

Practice

ALGEBRA 1

Simplify.

1. –8(–7) 2. –6(–7 + 10) – 4

Evaluate each expression for m = –3, n = 4, and p = –1.

3. + p 4. (mp)3 5. mnp

6. Evaluate 2a ÷ 4b – c for a = –2, b = – , and c = –

56 – 22

–7 27 12

8mn

13

12

312

Multiplying and Dividing Real NumbersLESSON 1-6

Lesson Quiz

.