28.
29.
Just in case is not clear the equation is:
2
Solve for l
32.
33.
Home-Learning Review:
Quiz #3a:
Convert the given amount to the given unit:
1. 200 cm = ______ meters?
2. 5 ft 3 in = _________ in?
Solve each proportion:
3.
5.
32
4.
y
36
45
Hint:
Quiz #3b:
lb = pound
oz = ounces
Convert the given amount to the given unit:
1. 6 ½ ft = ______ in?
2. 4 lb 7 oz = _________ oz?
Solve each proportion:
3.
5.
32
4.
y
36
45
Name:
Date:
Period:
Topic: Percent and Change Expressed as a percent
Essential Question: What strategies could help you solve a percent problem or a percent change?
Vocabulary:
Percentage =
%
A percentage is a fraction in which the denominator is equal to 100.
For example, 7% 
7
100
Decimals to percentage:
Fractions to percentage:
3
4
.58
.08
1
2
YOUR TURN
Quick Review:
.04
.6
12
25
4
5
a
p

100
b
a = part of, b = base, p = percent
a=p·b
How do you
find the percent
using the percent
proportion?
What percentage of 56 is 42?
What percentage of 75 is 15?
A dress shirt that normally costs $38.50 is on sale for 30% off.
How do you
find the “a” part
using the percent
equation?
How do you
find the “b” part
using the percent
equation?
What is the sale price of the shirt?
A family sells a car to dealership for 60% less than they paid for it.
They paid $9000 for the car. For what price did they sell the car?
125% of what number is 17. 5?
20% of what number is 80?
YOUR TURN
1) What percentage of 16 is 10?
a = part of
b = base
p = percent
a=p·b
2) What percentage of 48 is 20?
3) As you walk into a store you see the skate board you always
wanted at a 35% discount from its original price of $39.99.
What is the sale price of the skateboard?
4) 60% of what number is 13.5?
5) 150% of what number is 34?
If you need help do not hesitate to ask for help!
How do you
find simple
interest?
I = Prt
You deposited $840 in a savings account that earns a simple
interest rate of 4.5% per year. You want to keep the
money in the account for 4 years.
How much interest will you earn?
You deposited $125 in a savings account that earns a
simple interest rate of 1.75% per year.
You earned a total of $8.75 in interest.
For how long was your money in the account?
I = interest
P = principal
r = annual interest rate
t = time in years
YOUR TURN
6) A savings account earns simple interest at
a rate of 6% per year.
Last year the account earned $10.86 in interest.
What was the balance in the account at the beginning of last year?
Vocabulary:
Percentage
Change
Percentage change 
=
is the ratio of the amount of
change to the original amount .
New value  Original value
 100%
Original Value
Example:
Peter’s weight decreases from 60
kg to 48 kg.
Find the percentage change of his
weight.
If the answer is positive, it means a percentage increase. If
the answer is negative, it means a percentage decrease.
YOUR TURN
7) In one year, the toll for passenger cars
to use a tunnel rose from $3 to $3.50.
What was the percent increase?
8) The average monthly precipitation for Chicago,
Illinois, peaks in June at 4.1 in. The average monthly
precipitation in December is 2.8 in.
What is the percent decrease from June to December?
Real Life:
Profit and Loss
9) David bought a car
for $90,000 three years
ago. He sells the car for
$54,000 this year. What
is the percentage
change of his car’s price?
When the percentage
change is positive, it means
there is a profit.
When the percentage
change is negative, it means
there is a loss.
Still Your Turn!
Real Life:
Percent Error
Percentage Error  Estimated Value  Actual Value 100%
Actual Value
10) A decorator estimates that a
rectangular rug is 5ft by 8ft. The rug is
actually 4ft by 8ft. What is the percent
error in the estimated area?
A) 0.25%
B) 20%
C) 25%
D) 80%
Yeah, You Know It. It’s Your Turn!
Independent Practice:
Page 137 Solve It – Getting Ready
Page 148 (8, 16, 17, 18)
Page 149 (28, 39)
Page 150 (42)
Group 1:
Pair Work:
Group 6:
103ft; yd
Presentations
30 meters; cm
12 lb 3 oz; oz
Group 2:
Group 7:
If 5 pizzas serve 14 people, how many
pizzas are needed for a pizza party with
76 people?
• 15% of what number is 74?
• What is 30% of 241
Group 8:
A beauty salon buys bottles of
styling gel for $6. 35 per
bottle and marks up the price
by 35%. For what price does
the salon sell each bottle?
Group 3:
You are planting a vegetable garden with 12 rows.
If it took 26 minutes to plant the first 4 rows, how
long will it take to plant all 12 rows of the garden?
Group 4:
270 min; hours
43 km; cm
5000 centimeters; meters
Group 5:
Find the percent change: A
$1700 computer is on sale
for $1175.
Group 9:
You deposit $645 in a savings
account that earns simple
interest at a rate of 3.5% per
year. How much interest will
you have earned after 7 years?
Group 10:
Find the percent change: The value of a
stamp collection increases from $150 to
$170 in one year
Wrap-Up:
Vocabulary Review
Test Reminder
HLA#9:Conversions, Proportions, & Percents
Page 155-156 (40, 46, 49, 54, 60)