1. Do Now 2/20/14 Take out your HW from last night.
6.6 Puzzle Time Practice
Copy HW in your planner.
Text p. 248, #7-16 all, 19, 20
In your notebook, put the following heading on the top of a new page. Section 6.4 “Percent of Change”

2. Homework Puzzle Time 6.6 1) $59.40 2) $57.60 3) $53.10 4) $97.50
5) $68.25
6) $58
7) $24.50
8) $42
9) $44
10) $36
11) $3.12
12) $2842
13) $11.99
14) $
15) $735
“What Does A Monster Say When Introduced?”
PLEASED TO EAT YOU

3. Objective
SWBAT solve problems involving percent of change

4. Section 6.4 “Percent of Change”
the amount that a number increases or decreases written as a percent
amount of change
original amount
Percent of change =
x 100
If the amount goes up, it is a PERCENT of INCREASE.
If the amount goes down, it is a PERCENT of DECREASE.

5. Amount of change Original amount x 100 Before: 30 After: 45
Find the percent of increase or decrease (round to the nearest tenth of a %).
Before: After: 45
50% increase
Before: After: 46
60% decrease
Before: After: 146
25.9% increase

6. ≈0.181818 actual change original amount 200 1100 = ≈18.2% increase
The enrollment of Howell Middle School South in
was 1100 students. In the year
the enrollment was 1300 students.
What is the percent of increase or decrease between
the two years?
From to the
enrollment increased by 200, therefore
our answer is a percent of increase. :
: – 1100
change: ≈
actual change
original amount
200
1100
Percent of increase = =
≈18.2% increase

7. amount of change original amount 0.2 million 2 million =0.1 =10%
There were 2.2 million computers used in public schools in 1991 and 2 million in Find the percent of increase.
From 1990 to 1991 the number of computers
used increased by 0.2 million or 200,000.
1991: million
1990: million
change: million or 200,000.
amount of change
original amount
0.2 million
2 million
=0.1
Percent of increase =
=10%
increase

8. Scenario 3: amount of change original amount $9.20 $307.99 =0.0298711
If a customer brings an ad that shows a competitor is selling an item for less, you are permitted to match the competitor's price as long as the percent of discount is 15% or less.
a). The newest Blu-ray disc player is listed at $ You notice on your way to work that the same player is for sale at another store for $ Would you be allowed to match this store's price if asked? Explain.
amount of change
original amount
$9.20
$307.99 =
Percent of decrease =
≈3% decrease
Yes, you would be permitted to match the price of $

9. Scenario 3: =$59.97 x 5% shipping = $62.97 amount of change
If a customer brings an ad that shows a competitor is selling an item for less, you are permitted to match the competitor's price as long as the percent of discount is 15% or less.
b). The store sells a wireless Internet router for $ A customer has printed out a page from the Internet that shows the same router for $59.97 plus 5% shipping and handling. Can you match this price? Explain.
=$59.97 x 5% shipping
= $62.97
amount of change
original amount
$11.78
$74.75
= …
Percent of decrease =
≈16% decrease
No, you would not be permitted to match the price on the Internet because the discount is greater than 15%.

10. Percent Applications
There were about 198,000 spectators at the NCAA Final Four in The number of spectators increased by about 12% from 1995 to About how many spectators were there in 2002?
Spectators in 2002 =
Spectators in 1995 +
Amount of increase =
198,000 + =
198,000 +
23,760 =
221,760

11. Percent Applications
In 1983, the average price of CD was $ By 2000, the average price had decreased by 34.8%. What was the average price of a CD in 2000?
Price in 2000 =
Price in 1983 -
Amount of Decrease =
$21.50 - =
$21.50 -
7.48 =
$14.02

12. 24
Homework
Text p. 248, #7-16 all, 19, 20