Transparency 4 Click the mouse button or press the Space Bar to display the answers.

Click the mouse button or press the Click the mouse button or press the Space Bar to display the answers.Space Bar to display the answers.

Objective

Multiply Integers

Vocabulary

None

Multiply Integers

1. Same Sign

Positive Answer

2. Different Signs

Negative Answer

3 4 = 12

-3 -4 = 12

3 -4 = -12

-3 4 = -12

Example 1 Multiply Integers with Different Signs

Example 2 Multiply Integers with Different Signs

Example 3 Multiply Integers with Same Signs

Example 4 Multiply Integers with Same Sings

Example 5 Use Integers to Solve a Problem

Answer:

Opposite Signs

Multiply numbers without signs9 6

54 Opposite signs , negative answer-

Write problem

9 ( - 6 ) Draw arrows to signs

Identify signs

1/5

Find 9 (-6)

Answer: –28

1/5

Find 4 (-7)

Answer:

Opposite Signs

Multiply numbers without signs5 7

35-

Write problem

- 5 7 Draw arrows to signs

Identify signs

Opposite signs , negative answer

2/5

Find - 5 7

Answer: –24

2/5

Find - 8 3

Answer:

Same Signs

Multiply numbers without signs7 9

63+

Write problem

7 9 Draw arrows to signs

Identify signs

Same signs, positive answer

3/5

Find 7 9

Answer: 20

3/5

Find 5 4

Answer:

Same Signs

Multiply numbers without signs4 8

32+

Write problem

- 4 ( - 8 ) Draw arrows to signs

Identify signs

Same signs, positive answer

4/5

Find - 4 (- 8)

Answer: 14

4/5

Find - 2 (- 7)

ELEVATORS An elevator takes passengers from the ground floor of a mall down to the underground parking garage. If it travels at a rate of 5 feet per second, where will it be in relation to the ground floor after 2 seconds?

- 5 2

5/5

Determine process to use

“Rate” refers to distance multiplied by time

Identify distance

Elevator is going down so number is negative

Identify time

Answer:

Opposite Signs Multiply numbers without signs

5 2

10-

- 5 2Draw arrows to signs

Identify signs

Opposite signs , negative answer

5/5

If it travels at a rate of 5 feet per second,

Add dimensional analysisfeet

Distance is in feet

INVESTMENTS Mr. Green has invested in a stock whose price is decreasing at a rate of $3 per day. What will be the change in the price of the stock after 5 days?

Answer: – $15

*

5/5

Assignment

Lesson 8:4 Multiplying Integers 11 - 31 All