Post on 31-Dec-2015
description
Today’s Plan:-Warm Up-Percent -Assignment & Flashcard race
LT: I will use a proportion to solve percent problems.
Entry Task
04/12/10 Percent Calculations #28
Find the percent of each number.
1. 25% of 8
2. 40% of 110
3. 150% of 96
4. 0.3% of 120
44
2
144
0.36
Course 2
6-4 Solving Equations Containing Percents
Sloths may seem lazy, but their extremely slow movement helps to make them almost invisible to predators. Sloths sleep an average of 16.5 hours a day. To find out what percent of a 24-hour day 16.5 hours is, you can use a proportion or an equation.
Course 2
6-4 Solving Equations Containing Percents
Percent is
of
Sloths spend 68.75% of the day sleeping!
16.5 is what percent of 24 hours?
%100
= isof
x
100
16.5
24=
Course 2
6-4 Solving Equations Containing Percents
white boards…
%100
= isof
Course 2
6-4 Solving Equations Containing Percents
A. 25 is what percent of 40?
100=
62.5%
25 is 62.5% of 40.
%100
= isof
x 2540
Course 2
6-4 Solving Equations Containing Percents
B. 15 is 25% of what number?
x = 60
15 is 25% of 60.
Write a proportion.
%100
= isof
100=25 15
x
Solve.
Try This: Example 1A
Course 2
6-4 Solving Equations Containing Percents
A. 10 is what percent of 50?n
100= 10
50
n = 20
10 is 20% of 50.
Write a proportion.
Solve.
Try This: Example 1B
Course 2
6-4 Solving Equations Containing Percents
B. 8 is 40% of what number?
40100
= 8n
n = 20
8 is 40% of 20.
Write a proportion.
Today’s Plan:-Warm Up-Percent -Assignment & Flashcard race
LT: I will use a proportion to solve percent problems.
AssignmentPg 318 #1-21 and 23
For each problem show the proportion and your answer.
04/12/10 Percent Calculations #28
%100
= isof
Course 2
6-4 Solving Equations Containing Percents
Proportion Method Equation Method
n100
= 16.524
PartWhole
PartWhole
What percent of 24 is 16.5?
n · 24 = 100 · 16.5
24n = 1,650
n = 68.75 68.75%
n · 24 = 16.5
n = 0.6875
n = 68.75%
Solve.
Additional Example 2A: Using Equations to Solve Problems with Percents
Course 2
6-4 Solving Equations Containing Percents
A. 35 is 28% of what number?
35 = 28% · n
35 = 0.28 · n
350.28
= 0.28 · n0.28
125 = n
35 is 28% of 125.
Write an equation.
Write 28% as a decimal.
Divide each side by 0.28 to isolate the variable.
Solve.
Additional Example 2B: Using Equations to Solve Problems with Percents
Course 2
6-4 Solving Equations Containing Percents
B. 18 is what percent of 9?
18 = n · 9
189
= n · 99
2 = n
200% = n
18 is 200% of 9.
Write an equation.Divide each side by 9 to isolate the variable.Write the decimal as a percent.
Solve.
Try This: Example 2A
Course 2
6-4 Solving Equations Containing Percents
A. 36 is 24% of what number?
36 = 24% · n
36 = 0.24 · n
150 = n
36 is 24% of 150.
Write an equation.
Write 24% as a decimal.
Divide each side by 0.24 to isolate the variable.
360.24
= 0.24 · n0.24
Solve.
Try This: Example 2B
Course 2
6-4 Solving Equations Containing Percents
B. 36 is what percent of 6?
36 = n · 6
366
= n · 66
6 = n
600% = n
36 is 600% of 6.
Write an equation.Divide each side by 6 to isolate the variable.Write the decimal as a percent.
Workers in Canada earn 10 vacation days, and workers in Finland earn 30 vacation days. What percent of the vacation days that workers in Canada earn do workers in Finland earn?
Additional Example 3: Social Studies Application
Course 2
6-4 Solving Equations Containing Percents
n · 10 = 30
n · 1010
= 3010
n = 3.0
Workers in Finland earn 300% of the number of vacation days that workers in Canada earn.
Write an equation.
Divide each side by 10 to isolate the variable.
Write the decimal as a percent.
Restate the question: What percent of 10 is 30?
n = 300
Workers in Canada earn 10 vacation days, and workers in Britain earn 20 vacation days. What percent of the vacation days that workers in Canada earn do workers in Britain earn?
Try This: Example 3
Course 2
6-4 Solving Equations Containing Percents
n · 10 = 20
n · 1010
= 2010
n = 2.0
Workers in Britain earn 200% of the number of vacation days that workers in Canada earn.
Write an equation.
Divide each side by 10 to isolate the variable.
Write the decimal as a percent.
Restate the question: What percent of 10 is 20?
n = 200
Lesson Quiz
1. 21 is 42% of what number?
2. 73 is what percent of 292?
3. 112% of what number is 84?
4. 13.4 is what percent of 1340?
5. An ad shows a DVD player on sale for 75% of its original price. If its original price was $242, what is the sale price?
25%
50
Insert Lesson Title Here
75
1%
Course 2
6-4 Solving Equations Containing Percents
$181.50