9/12/12 Warm-Up
1.
– 17.3 + 6.2 =
ANSWER
2.
For use with pages xxx–xxx
Find
– 21 – 17
ANSWER
– 11.1
26.9 – ( – 5.8 ) =
ANSWER
4.
?
– 38
?
32.7
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
5.
9900 ft
ANSWER
11.8
ALGEBRA GAME PLAN
Date
Section
9/9/13 Monday
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, #1-12 (choose 5), 32 – 39 (choose 3),
Announcement
Quiz, Wednesday 9/11
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
+9
the answer is
negative
-36
ALGEBRA 1
Math Dog
(Multiply or Divide)
-24  -3
-24
-3
the answer is
positive
8
ALGEBRA 1
Multiplying and Dividing Real Numbers
LESSON 1-6
Additional Examples
Simplify each expression.
a. –3(–11)
3
b. –6( 4 )
–3(–11) = 33
The product of two negative numbers is
positive.
–6( 3 ) = – 18
The product of a positive number and a
negative number is negative.
4
4
=_9
2
ALGEBRA 1
Multiplying and Dividing Real Numbers
LESSON 1-6
Additional Examples
Practice
Simplify each expression. (choose
4)
1)
2)
3)
4)
5)
6)
7)
8)
-8(3)
4(-4)
-20(-6 + 2)
-7(-1.2)
-11(⅛)
15(-⅗)
| (-12)2 |
| (-10)(-5) |
Answers
1)
2)
3)
4)
5)
6)
7)
8)
-24
-16
80
8.4
-11/8
-9
24
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
Multiplying and Dividing Real Numbers
LESSON 1-6
Additional Examples
Use the order of operations to simplify each expression.
I DO
a. –0.24 = –(0.2 • 0.2 • 0.2 • 0.2)
= –0.0016
Write as repeated multiplication.
Simplify.
WE DO
b. (–0.2)4= (–0.2)(–0.2)(–0.2)(–0.2)
= 0.0016
Write as repeated multiplication.
Simplify.
ALGEBRA 1
Multiplying and Dividing Real Numbers
LESSON 1-6
Additional Examples
Use the order of operations to simplify each expression.
YOU DO
TOGETHER
a. (–0.3)3
(–0.3)(–0.3)(–0.3)
= –0.027
b. –0.33 = –(0.3 • 0.3 • 0.3)
= -0.027
ALGEBRA 1
Multiplying and Dividing Real Numbers
LESSON 1-6
Additional Examples
Simplify each expression.
a. 100 ÷ (–5)= –20
b. –54 ÷ (–9) = 6
The quotient of a positive number and a
negative number is negative.
The quotient of a negative number and a
negative number is positive.
ALGEBRA 1
Multiplying and Dividing Real Numbers
LESSON 1-6
Additional Examples
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)
Practice
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
RECIPROCAL
of that number.
ALGEBRA 1
Find the Multiplicative Inverse
1.
2.
3.
4.
⅘
-7
⅚
-⅓
5/
4
-1/7
6/
5
1.
2.
3.
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
Simplify
1. -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?
Answers
1. -52
2. 56
3. -6
4. 50
5. -21
6. .reciprocal
ALGEBRA 1
ALGEBRA GAME PLAN
Date
Section
9/10/13 Tuesday
Objective
Students will be able to multiply and divide real
numbers.
1-6: Multiplying and Dividing Real Numbers
Algebra
California
Standard
Homework P 41 – 44: Choose 2 from each set
Announcement
(18-24), (25-30), (48-53)
Everyone must do 54, 61, 97, 98
Quiz, Wednesday 9/11
Multiplying and Dividing Real Numbers
LESSON 1-6
Additional Examples
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.
ALGEBRA 1
Multiplying and Dividing Real Numbers
LESSON 1-6
Additional Examples
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.
ALGEBRA 1
Practice
ALGEBRA 1
Multiplying and Dividing Real Numbers
LESSON 1-6
Additional Examples
Use the expression –5.5( 1000 ) to calculate the
change in temperature for an increase in altitude a of
7200 ft.
a
a
–5.5( 1000
7200
) = –5.5 ( 1000 )
Substitute 7200 for a.
= –5.5(7.2)
Divide within parentheses.
= –39.6°F
Multiply.
The change in temperature is –39.6°F.
ALGEBRA 1
Multiplying and Dividing Real Numbers
LESSON 1-6
Additional Examples
x
Evaluate – y – 4z2 for x = 4, y = –2, and z = –4.
–4
– x – 4z2 = –2 – 4(–4)2
y
–4
Substitute 4 for x, –2 for y, and –4 for z.
= –2 – 4(16)
Simplify the power.
= 2 – 64
Divide and multiply.
= –62
Subtract.
ALGEBRA 1
Multiplying and Dividing Real Numbers
LESSON 1-6
Additional Examples
Evaluate p for p = 3 and r = – 3 .
r
p
r =p÷r
3
4
Rewrite the equation.
= 3 ÷ (– 3 )
2
2
4
Substitute 3 for p and – 3 for r.
2
4
= 2 (– 4 )
3
Multiply by – 4 , the reciprocal of – 3 .
= –2
Simplify.
3
4
ALGEBRA 1
Practice
ALGEBRA 1
Multiplying and Dividing Real Numbers
LESSON 1-6
Lesson Quiz
Simplify.
1.
–8(–7)
56
2. –6(–7 + 10) – 4
– 22
Evaluate each expression for m = –3, n = 4, and p = –1.
3. 8m + p
n
–7
4. (mp)3
5. mnp
27
12
6. Evaluate 2a ÷ 4b – c for a = –2, b = – 1 , and c = – 1 .
3
2
1
32
ALGEBRA 1