Transcript Tuesday, Oct 30 - Xenia Community Schools

5 Minute Check
Find. Round to the nearest tenth, if
necessary. Complete in your notes.
1. 9 is what percent of 72?
2. What percent of 96 is 24?
3. 17 is 40% of what number?
4. 80% of what number is 64?
5 Minute Check
Find. Round to the nearest tenth, if
necessary. Complete in your notes.
1. 9 is what percent of 72?
5 Minute Check
Find. Round to the nearest tenth, if
necessary. Complete in your notes.
1. 9 is what percent of 72?
part = percent (in decimal form) x whole
9 = p · 72
.125
72
72
8)1.00
1 = p
8
12.5% = p
-8
20
-16
40
5 Minute Check
Find. Round to the nearest tenth, if
necessary. Complete in your notes.
2. What percent of 96 is 24?
5 Minute Check
Find. Round to the nearest tenth, if
necessary. Complete in your notes.
2. What percent of 96 is 24?
part = percent (in decimal form) x whole
24 = p · 96
96
96
1 = p
4
25% = p
5 Minute Check
Find. Round to the nearest tenth, if
necessary. Complete in your notes.
3. 17 is 40% of what number?
5 Minute Check
Find. Round to the nearest tenth, if
necessary. Complete in your notes.
3. 17 is 40% of what number?
17 = .40 · w
.40
.40
42.5
40)1700.0
42.5 = w
-160
100
-80
200
5 Minute Check
Find. Round to the nearest tenth, if
necessary. Complete in your notes.
4. 80% of what number is 64?
5 Minute Check
Find. Round to the nearest tenth, if
necessary. Complete in your notes.
4. 80% of what number is 64?
64 = .80 · w
80.0
.80
.80
80)6400.0
-640
80 = w
00
Monday, Feb 2
Lesson 7.2.5
Percent of Change
Solve One-Step Inequalities
Solve One-Step Inequalities
Solve One-Step Inequalities
Solve One-Step Inequalities
Solve One-Step Inequalities
Solve One-Step Inequalities
Percent of Change
Objective: To understand the percent of
change and percent of error.
Percent of Change
A percent of change is a ratio that compares
the change in quantity to the original amount.
Write this down.
Percent of Change
Yusuf bought a DVD recorder for $280.
Now it is on sale for $210. Find the percent
of change in the price.
How to Find the Percent of Change.
Step 1 – Find the change. Changed number
minus original number.
Percent of Change
Yusuf bought a DVD recorder for $280.
Now it is on sale for $210. Find the percent
of change in the price.
$210 - $280 = - $70
How to Find the Percent of Change.
Step 1 – Find the change. Changed number
minus original number.
Percent of Change
Yusuf bought a DVD recorder for $280.
Now it is on sale for $210. Find the percent
of change in the price.
$210 - $280 = - $70
How to Find the Percent of Change.
Step 2 – Create a ratio with the change over
the original amount.
Percent of Change
Yusuf bought a DVD recorder for $280.
Now it is on sale for $210. Find the percent
of change in the price.
$210 - $280 = - $70
− $70
$280
How to Find the Percent of Change.
Step 2 – Create a ratio with the change over
the original amount.
Percent of Change
Yusuf bought a DVD recorder for $280.
Now it is on sale for $210. Find the percent
of change in the price.
$210 - $280 = - $70
−$70
$280
How to Find the Percent of Change.
Step 3 – Simplify.
Percent of Change
Yusuf bought a DVD recorder for $280.
Now it is on sale for $210. Find the percent
of change in the price.
$210 - $280 = - $70
−$70
$280
=-
1
4
How to Find the Percent of Change.
Step 3 – Simplify.
Percent of Change
Yusuf bought a DVD recorder for $280.
Now it is on sale for $210. Find the percent
of change in the price.
$210 - $280 = - $70
−$70
$280
=-
1
4
How to Find the Percent of Change.
Step 4 – Convert to a percent.
Percent of Change
Yusuf bought a DVD recorder for $280.
Now it is on sale for $210. Find the percent
of change in the price.
.25 = 25%
$210 - $280 = - $70
−$70
$280
1
4
= - = -25%
4)1.00
-8
20
The price decreased by 25%
How to Find the Percent of Change.
Step 4 – Convert to a percent.
Percent of Change
Find the percentage of change from 10 yards
to 13 yards.
Step 1 - ?
Percent of Change
Find the percentage of change from 10 yards
to 13 yards.
13 - 10 = 3
Step 2 - ?
Percent of Change
Find the percentage of change from 10 yards
to 13 yards.
13 - 10 = 3
3
10
Step 3 - ?
Percent of Change
Find the percentage of change from 10 yards
to 13 yards.
13 - 10 = 3
3
10
Step 4 - ?
Percent of Change
Find the percentage of change from 10 yards
to 13 yards.
13 - 10 = 3
3
10
= 30% increase
.30 = 30%
10)3.00
-30
0
Percent of Change
The price of a radio was $120. It is on sale for
$102. What is the percent of change in the
price of the radio?
Do this on your own.
Percent of Change
The price of a radio was $120. It is on sale for
$102. What is the percent of change in the
price of the radio?
102 - 120 = -18
−18
120
=-
3
20
= - 15%
A 15% decrease.
.15 = 15%
20)3.00
-20
100
Percent of Change
66 feet to 26.4 feet.
Do this on your own.
Percent of Change
66 feet to 26.4 feet.
26.4 - 66= - 39.6
−39.6
66
= - 60%
A 60% decrease
.6 = 60%
66)39.6
-396
0
Percent of Change
Find the percent of change in the perimeter of
the square if the sides decreased by 1 inch.
3 in.
Percent of Change
Find the percent of change in the perimeter of
the square if the sides decreased by 1 inch.
SQ 1
4(3) =12 in
SQ 2
4(2) = 8 in
8 – 12 = - 4
−4
1
=
33
%
12
3
1
3
A 33 % decrease
3 in.
Percent of Change
Find the percent of change in the perimeter of
the square if the sides decreased by 1 inch.
What is the change in area?
3 in.
Percent of Change
Find the percent of change in the perimeter of
the square if the sides decreased by 1 inch.
What is the change in area?
SQ 1
3·3 =9 in²
SQ 2
2·2 = 4 in²
4–9=-5
−5
=
55.5%
9
A 56 % decrease
3 in.
.55
9)5.0
-45
50
Percent of Change
Use the graph shown to find the percent of
change in CD sales from 2011 to 2012.
Round to the nearest tenth.
Do this on your own.
Percent of Change
Use the graph shown to find the percent of
change in CD sales from 2011 to 2012.
Round to the nearest tenth.
=
A 4.2% decrease.
−12
283
= -0.0424 = -4.2%
Percent of Change
A percent of error is a ratio that compares
inaccuracy of an estimate, or amount of error, to
the actual amount.
Write this down.
Generally, the percent of error does not
determine whether it is an increase or decrease.
Percent of Change
Finding the percent of error is similar to
finding the percent of change.
Percent of Change
Ahmed wants to practice free throws. He
estimates the distance from the free throw
line to the hoop and marks it with chalk.
Ahmed’s estimate was 13.5 feet. The actual
distance should be 15 feet. Find the percent
error.
Percent of Change
Ahmed wants to practice free throws. He
estimates the distance from the free throw
line to the hoop and marks it with chalk.
Ahmed’s estimate was 13.5 feet. The actual
distance should be 15 feet. Find the percent
error.
𝑓𝑡
= 1.5
=
0.1
=
10%
15 𝑓𝑡
Percent of Change
Find the percent error if the estimate was
$285 and the actual amount was $300.
Do this on your own.
Percent of Change
Find the percent error if the estimate was
$285 and the actual amount was $300.
15
= 300
= 0.05 = 5%
Percent of Change
Each week, Mr. Jones goes to the grocery
store. Mr. Jones estimates he will spend
$120 when he goes to the grocery store this
week. He actually spends $94. What is the
percent of error rounded to the tenth?
Do this on your own.
Percent of Change
Each week, Mr. Jones goes to the grocery
store. Mr. Jones estimates he will spend
$120 when he goes to the grocery store this
week. He actually spends $94. What is the
percent of error rounded to the tenth?
= 26
= 0.2765 = 27.7%
94
Percent of Change
Johanna’s parents give her $10 per week for lunch money.
The costs of two sound systems were decreased by $10. The
original costs of the systems were $90 and $60. Without
calculating, which had the greater percent of decrease?
Explain.
Percent of Change
Johanna’s parents give her $10 per week for lunch money.
The costs of two sound systems were decreased by $10. The
original costs of the systems were $90 and $60. Without
calculating, which had the greater percent of decrease?
Explain.
The $60 system. $10 is a greater part of $60 than $90.
Percent of Change
Johanna’s parents give her $10 per week for lunch money.
Without using a calculator, arrange the following from
greatest to least value. Justify your answer.
20% of 100, 20% of 500, 5% of 100
Percent of Change
Johanna’s parents give her $10 per week for lunch money.
Without using a calculator, arrange the following from
greatest to least value. Justify your answer.
20% of 100, 20% of 500, 5% of 100
Percent of Change
Agenda Notes
Homework Practice 7.2.5
Due Tuesday, Feb 3
Chapter 7.2/7.3 Test - Tuesday, Feb 10