1. Do Now 4/20/10 Take out HW from last night. Copy HW in your planner.
Text p. 792, #1-8 all
Text p. 793, #1-6 all
Copy HW in your planner.
Text p. 355, #8-24 evens

2. Skills Review Handbook “Angles and Measurement”
There are 4 types of angles:
Acute angle – has a measure of less than 90°
Right angle – has a measure of exactly 90°
Obtuse angle – has a measure of more than 90°
Straight angle – has a measure of exactly 180°

3. Skills Review Handbook “Angles and Measurement”
Use a protractor to measure an angle.

4. Skills Review Handbook “Units of Measurement”
Text p. 792, #1-8 all
Text p. 793, #1-6 all
1) 38°
2) 134°
3) 84°
4) 52° 5) 6) 7) 8)
1) 92°; obtuse
2) 180°; straight angle
3) 61°; acute
4) 157°; obtuse
5) 126°; obtuse
6) 135°; obtuse
55°
168°
90°
77°

5. Chapter 7 “Percents” Section 7.1 “Percents and Fractions”
Section 7.2 “Percents and Proportions”
Section 7.3 “Percents and Decimals”
Section 7.4 “The Percent Equation”
Section 7.5 “Percent of Change”
Section 7.6 “Percent Applications”
Section 7.7 “Simple and Compound Interest”

6. Objective
SWBAT find a percent of change in a quantity

7. Section 7.5 “Percent of Change”
Percent of change indicates how much a quantity increases or decreases with respect to the original amount.
The percent of change of a quantity is given by:
The percent is a PERCENT of INCREASE if the quantity increased and it is a PERCENT of DECREASE if the quantity decreased.
Amount of change
Original amount
x 100

8. Amount of change Original amount x 100 Before: 30 After: 45
The percent of change of a quantity is given by:
Amount of change
Original amount
x 100
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

9. Amount of change Original amount x 100
The percent of change of a quantity is given by:
Amount of change
Original amount
x 100
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% increase

10. Amount of change Original amount x 100
The percent of change of a quantity is given by:
Amount of change
Original amount
x 100
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

11. Who is Watching MTV??? Find the percent of change from 1985 to 1987.
Decrease 31.25%
Increase 24%

12. Using a Percent of Change
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 +
(12% · 198,000) =
198,000 +
23,760 =
221,760

13. Using a Percent of Change
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 x
Percent of change =
$21.50 x
(100% – 34.8%) =
$21.50 x
65.2% =
$ = $14.02

14. 24
Homework
Text p. 355, #8-24 evens

15. Homework Why Did the Sea Monster Eat 27 Ships Carrying Potatoes?
NOBODY CAN EAT JUST … ONE POTATO SHIP
What Magic Trick Did Poof the Great Perform When He Visited Helsinki?
HE VANISHED INTO FINN AIR