Splash Screen. Chapter Menu Lesson 7-1Lesson 7-1Percent of a Number Lesson 7-2Lesson 7-2The Percent...

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Lesson 7-1 Percent of a Number

Lesson 7-2 The Percent Proportion

Lesson 7-3 Percent and Estimation

Lesson 7-4 Algebra: The Percent Equation

Lesson 7-5 Problem-Solving Investigation: Determine Reasonable Answers

Lesson 7-6 Percent of Change

Lesson 7-7 Sales Tax and Discount

Lesson 7-8 Simple Interest

• Find the percent of a number.

• In a survey, 54 out of 100 people responded “Yes.”  What percent responded “Yes?”

• 100 students were tested, and 36 got A.  What percentgot A?

• Jackie had $100 and spent $12.50 for lunch? What percent of her $100 did she spend for lunch?

P. 346 – 3489-27 ODD

Percent: A fraction whose denominator is 100.

HW: P. 346: 1-7 ALL

Change Percent to a number: Divide by 100.

Find the Percent of a Number

Find 8% of 125.

Method 1 Write the percent as a fraction.

Find the Percent of a Number

So, 8% of 125 is 10.

Answer: 10

Method 2 Write the percent as a decimal.

Interactive Lab: Percent of a Number

What is 5 percent of 300?

100

5

20

1=5% =

5% = 0.05

0.05 · 300 = 15

20

1 of 300 =

20

1 · 1

300= 15

20

300=

Find 25% of 96.

100

25

4

1=25% =

25% = 0.25

0.25 · 96 = 24

4

1 of 96 =

4

1 · 1

96= 24

4

96=

Find 120% of 75.

100

120

5

6=120% =

120% = 1.2

1.2 · 75 = 90

5

6 of 75 =

5

6 · 1

75= 90

5

450=

Find 8.9% of 75.

100

8.98.9% =

8.9% = 0.089

0.089 · 75 = 6.675

100

8.9 of 75 =

100

8.9 · 1

75= 6.675

100

667.5=

Find 97.5% of 80.

100

97.597.5% =

97.5% = 0.975

0.975 · 80 = 78

100

97.5 of 80 =

100

97.5 · 1

80= 78

100

7800=

A community has a population of 5000. 60% voted. How many people voted?

100

60

5

3=60% =

60% = 0.6

0.6

· 5000 = 3000

5

3 of 5000 =

5

3 · 1

5000 = 300005

15000=

Mr. Redding sells cars to 20% of the people who come to his showroom. If 65 people came to his showroom, how many vehicles did he sell?

100

20

5

1=20% =

20% = 0.2

0.2

· 65 = 13

5

1 of 65 =

5

1 · 1

65= 13

5

65=

El Rodeo School’s Chess Club has 55 members. 22 are in 7th grade. What percent are in 7th grade?

55

22Part

Whole 100

n=22 100· = 55 ·n

2200 = 55n55 55

40% n=

2200 = 55n

In the city of Los Angeles, 75% of the parks have tennis courts. If 15 parks have tennis courts, how many parks does Los Angeles have?

n

15Part

Whole 100

75=n 75· = 15 ·100

75n = 150075 75

n 20=

75n = 1500

Linda’s bill at the restaurant is $23.40. She plans to tip the waiter 15%. How much should she leave?

23.40

nPart

Whole 100

15=23.40 15· = 100·n

351 = 100n100 100

$3.51 n=

351 = 100n

A. A

B. B

C. C

D. D0% 0%0%0%

A. 116

B. 252

C. 308

D. 335

Find 72% of 350.

Use Percents Greater Than 100%

Find 125% of 64.

Method 1 Write the percent as a fraction.

Use Percents Greater Than 100%

Method 2 Write the percent as a decimal.

So, 125% of 64 is 80.

Answer: 80

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. 225

B. 175

C. 112.5

D. 78.5

Find 225% of 50.

LANGUAGES The graph below shows that 30% of the people in a community speak Spanish as their first language. If a community has 800 people, how many people can be expected to speak Spanish as their first language?

To find 30% of 800, write the percent as a decimal. Then multiply.

30% of 800 = 30% ● 800

= 0.30 ● 800

= 240

So, 240 people can be expected to speak Spanish as their first language.

Answer: 240

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. 41.54

B. 33

C. 21.8

D. 20.46

SLEEP The average person sleeps 33% of their adult life. If their adult life consists of 62 years, how many years does the average person spend sleeping?

Five-Minute Check (over Lesson 7-1)

Main Idea and Vocabulary

California Standards

Example 1: Find the Percent

Example 2: Find the Part

Example 3: Find the Whole

Example 4: Use Percent to Solve a Problem

Concept Summary: Types of Percent Problems

• percent proportion

• Solve problems using the percent proportion.

Find the Percent

What percent of 24 is 18?

The number 24 comes after the word of, so the whole is 24. You are asked to find the percent, so the part is the remaining number, 18.

Words What percent of 24 is 18?

Variable Let n represent the percent.

Proportion

Find the Percent

Write the proportion.

Simplify.

Answer: 75% of 24 is 18.

Find the cross products.

Simplify.

Divide each side by 24.

What percent of 15 is 9?

15

9Part

Whole 100

n=9 100· = 15 · n

900 = 15n15 15

60 n=

900 = 15n

Find the Part

What number is 30% of 150?

The percent is 30%. Since the number 150 comes after the word of, the whole is 150. You are asked to find the part.

Words What number is 30% of 150?

Variable Let p represent the part.

Proportion

Find the Part

Answer: 30% of 150 is 45.

Write the proportion.

Simplify.

Find the cross products.

Simplify.

Divide each side by 100.

What number is 40% of 120?

120

nPart

Whole 100

40=n 100· = 120·40

100n = 4,800100 100

n 48=

100n =4,800

Find the Whole

12 is 80% of what number?

The percent is 80%. The words what number come after the word of. So, you are asked to find the whole. Thus, 12 is the part.

Words 12 is 80% of what number?

Variable Let w represent the whole.

Proportion

Find the Whole

Answer: 12 is 80% of 15.

Write the proportion.

Simplify.

Find the cross products.

Simplify.

Divide each side by 80.

19 is 50% of what number?

n

19Part

Whole 100

50=19 100· = 50 ·n

1900 = 50n50 50

38 n=

1900 = 50n

What percent of 50 is 20?

50

20Part

Whole 100

n=20 100· = 50 ·n

2000 = 50n50 50

40 n=

2000 = 50n

220 is 95.3% of what number?

n

220Part

Whole 100

95.3=95.3 n· = 100·220

95.3n = 2200095.3 95.3

230.8 n≈

95.3n = 22000

What number is 25% of 20?

20

nPart

Whole 100

25=n 100· = 20 ·25

100n = 500100 100

n 5=

100n = 500

22% of what number is 24.2?

n

24.2Part

Whole 100

22=24.2 100· = 22 ·n

2420 = 22n22 22

110 n=

2420 = 22n

A. A

B. B

C. C

D. D0% 0%0%0%

A. 28%

B. 35%

C. 56%

D. 80%

What percent of 80 is 28?

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. 65

B. 115

C. 117

D. 245

What number is 65% of 180?

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. 14.4

B. 76

C. 90

D. 102.6

36 is 40% of what number?

BREAKFAST Sally read the nutrition facts on a box of her favorite cereal. Each cup of the cereal provides 7% of the recommended daily value of potassium. If a cup of cereal contains 260 milligrams of potassium, what is the recommended daily value of potassium?

You know that 260 milligrams is 7% of the recommended daily value. So, the problem asks 260 is 7% of what number? Thus, you need to find the whole.

So, the recommended daily value of potassium is 3,714 mg.

Answer: 3,714 mg

Write the proportion.

Find the cross products.

Simplify.

Divide each side by 7.

A. A

B. B

C. C

D. D0% 0%0%0%

A. $500

B. $1,250

C. $3,500

D. $5,000

FUND RAISER The students at Greenview Middle School have raised $250 so far in their annual fund raiser. This amount represents 5% of their goal. What is the fund raising goal for the students at Greenview Middle School?

Five-Minute Check (over Lesson 7-2)

Main Idea

California Standards

Example 1: Use Percents to Estimate

Example 2: Use Percents to Estimate

Example 3: Percents Greater Than 100 or Less Than 1

Example 4: Percents Greater Than 100 or Less Than 1

Example 5: Estimate Percent to Solve a Problem

• Estimate percents by using fractions and decimals.

Standard 6NS1.4 Calculate given percentages of quantities and solve problems involving discounts at sales, interest earned, and tips.

CONCERTS A town sold 407 tickets to a chamber music concert in the town square. Of the tickets sold, 61% were discounted for senior citizens. About how many senior citizens bought tickets for the concert?

You need to estimate 61% of 407.

Answer: about 240

HW: P. 358 – 360

11-31 ODD;

51- 69 ODD

A. A

B. B

C. C

D. D0% 0%0%0%

A. about $100

B. about $150

C. about $225

D. about $300

TAXES Michelle’s pay check was $590 and 27% was deducted for taxes. How much was deducted?

COINS Melinda calculated that 40% of the coins in her coin collection were minted before 1964. If there are 715 coins in her collection, about how many of them were minted before 1964?

You need to estimate 40% of 715.

Method 1 Use a fraction to estimate.

Round 715 to 700.

Multiply.

Method 2 Use 10% of a number to estimate.

Step 1 Find 10% of the number.

715 is about 700.

10% of 700 = 0.1 ● 700

= 70

Step 2 Multiply.

40% of 700 is 4 times 10% of 700.

4 ● 70 = 280

Answer: about 280

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. about $42

B. about $48

C. about $52

D. about $55

SAVINGS Suki saves 70% of her monthly allowance. If her monthly allowance is $58, about how much does she save?

Percents Greater Than 100 or Less Than 1

Estimate 173% of 60.

173% is about 175%.

Answer: 173% of 60 is about 105.

175% of 60

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. about 33

B. about 112

C. about 142

D. about 222

Estimate 142% of 80.

1% of 900 = 0.01 ● 900 Write 1% as 0.01.

= 9

Answer:

Percents Greater Than 100 or Less Than 1

A. A

B. B

C. C

D. D0% 0%0%0%

A. about 0.4

B. about 4

C. about 20

D. about 40

GAME ATTENDANCE Last season 96,081 people were in attendance at a college football game. About 0.25% of those were reporters from newspapers and television and radio stations. About how many reporters were at the game?

0.25% is one quarter of 1%.

1% of 96,000 = 0.01 ● 96,000 96,081 is about 96,000.

= 960

Answer: about 240 reporters

A. A

B. B

C. C

D. D0% 0%0%0%

A. about 15

B. about 35

C. about 69

D. about 350

CONCERT The attendance at a popular outdoor concert was recorded as 6,973. Of those attending, 0.5% were security personnel. About how many security people were present?

Five-Minute Check (over Lesson 7-3)

Main Idea and Vocabulary

California Standards

Example 1: Find the Part

Example 2: Find the Percent

Example 3: Find the Whole

Example 4: Apply the Percent Equation

Concept Summary: Types of Percent Problems

• percent equation

• Solve problems by using the percent equation.

Standard 6NS1.4 Calculate given percentages of quantities and solve problems involving discounts at sales, interest earned, and tips.

Standard 6AF1.1 Write and solve one-step linear equations in one variable.

Find the Part

What number is 46% of 200?

Estimate 0.5 ● 200 = 100

46% or 0.46 is the percent and 200 is the whole.

Let p represent the part.

Answer: 46% of 200 is 92.

part = percent ● whole

p = 0.46 ● 200 Write an equation.

p = 92 Multiply. The part is 92.

A. A

B. B

C. C

D. D

0% 0%0%0%

A. 72

B. 122

C. 360

D. 720

What number is 72% of 500?

Find the Percent

26 is what percent of 32?

Find the Percent

Answer: 26 is 81.25% of 32.

Let n represent the percent.

Simplify.

Write 0.8125 as a percent.

Write an equation.

Divide each side by 32.

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. 18%

B. 22.5%

C. 57.5%

D. 62%

18 is what percent of 80?

Find the Whole

12 is 40% of what number?

Let w represent the whole.

Answer: 12 is 40% of 30.

The whole is 30.

Write an equation.

Divide each side by 0.40.

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. 32.4

B. 36

C. 40

D. 54

36 is 90% of what number?

TELEVISIONS In the year 2000, 102.2 million homes in the United States had at least one television. Of these, 86% also had VCRs. How many homes had VCRs?

Words 86% of 102,200,000 is what number?

Variable Let n represent the number of homes.

Equation n = 0.86 ● 102,200,000

n = 0.86 ● 102,200,000 Write an equation.

Answer: The number of homes with VCRs is about 87.9 million.

= 87,892,000 Multiply. Use a calculator.

A. A

B. B

C. C

D. D0% 0%0%0%

A. 220

B. 2,200

C. 5,654

D. 20,046

COLLEGE A local college has an enrollment of 25,700 students. Of these students, 22% are from out of state. How many of the students are from out of state?

Five-Minute Check (over Lesson 7-4)

Main Idea

California Standards

Example 1: Determine Reasonable Answers

• Solve problems by determining reasonable answers.

Standard 6NS1.4 Calculate given percentages of quantities and solve problems involving discounts at sales, interest earned, and tips.

Standard 6MR3.1 Evaluate the reasonableness of the solution in the context of the problem.

Determine Reasonable Answers

FUND RAISER A soccer team is having a candy sale to raise funds to buy new shirts. The team gets to keep 25% of the sales. Each candy bar costs $1.50, and the team has sold 510 bars so far. If the shirts cost a total of $175, should the team order the shirts yet? Explain.Explore You know the shirts cost a total of $175 and that each candy bar costs $1.50. You know that the team has sold 510 bars so far and

that they get to keep 25% of the sales. You need to know if the team has enough money to order the shirts yet.

Plan Find how much the team has earned so far. Then find 25% of their sales.

Determine Reasonable Answers

Solve $1.50 ● 510 = $765

Find 25% of $765.

25% of 765 = 0.25 ● 765

= 191.25

The team gets to keep $191.25. Since this is more than the cost of the shirts, they should order the shirts.

Answer: Yes, they have earned more than $175.

Check Use a calculator to check.

The result is 191.25, so the answer is reasonable.

0.25 765ENTER×

A. A

B. B

C. C

D. D

0% 0%0%0%

A. yes

B. no

C. sometimes

D. not enough information

FIELD TRIP There are 392 students in the seventh grade at Hamilton Middle School. If 35% of the seventh grade will attend the class field trip, is it reasonable to say that about 170 students will attend the field trip?

Five-Minute Check (over Lesson 7-5)

Main Idea and Vocabulary

California Standards

Key Concept: Percent of Change

Example 1:Find Percent of Increase

Example 2:Find Percent of Decrease

Example 3:Solve a Problem Using Percent of Change

• percent of change

• percent of increase• percent of decrease

• Find the percent of increase or decrease.

Standard 6NS1.2 Interpret and use ratios in different contexts (e.g., batting averages, miles per hour) to show the relative sizes of two quantities,

using appropriate notations

Interactive Lab: Percent of Change

Find Percent of Increase

SHOPPING Last year a sweater sold for $56. This year the same sweater sells for $60. Find the percent of change in the cost of the sweater. Round to the nearest whole percent if necessary.

Since the new price is greater than the original price, this is a percent of increase. The amount of increase is 60 – 56 or $4.

Find Percent of Increase

Answer: The percent of increase in the price of the sweater is about 7%.

Simplify.

Substitution

Write 0.07 as a percent.

A. A

B. B

C. C

D. D0% 0%0%0%

A. 4% increase

B. 17% increase

C. 20% increase

D. 24% increase

DVDS Last year a DVD sold for $20. This year the same DVD sells for $24. Find the percent of change in the cost of the DVD. Round to the nearest whole percent if necessary.

Find Percent of Decrease

ATTENDANCE On the first day of school this year, 435 students reported to Howard Middle School. Last year on the first day, 460 students attended. Find the percent of change for the first day’s attendance. Round to the nearest whole percent if necessary.

Since the new enrollment figure is less than the figure for last year, this is a percent of decrease. The amount of decrease is 460 – 435 or 25 students.

Find Percent of Decrease

Answer: The percent of decrease in the enrollment is about 5%.

Simplify.

Substitution

Write 0.05 as a percent.

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. about 2% decrease

B. about 4% decrease

C. about 4% increase

D. about 2% increase

ZOO At the beginning of the summer season, the local zoo reported having 385 animals in its care. At the beginning of last year’s summer season, the zoo had reported 400 animals. Find the percent of change in the number of animals at the zoo. Round to the nearest whole percent if necessary.

The table shows the annual city budget of Layton for four years. Which statement is supportedby the table?

A The budget decreased and then increased.

B The greatest budget increase occurred from 2003 to 2004.

C The budget increased 15% from 2002 to 2005.

D The budget decreased about 3% from 2004 to 2005.

Read the Item

You need to determine which statement is best supported by the information given in the table.

Solve the Item

Check A The budget increased and then decreased. This option is not correct.

Check B The greatest budget increase occurred from 2002 to 2003, not from 2003 to 2004. This

option is not correct.

Check D The percent of decrease from 2004 to

2005 was or about 3%. This

option is correct.

Answer: D

Check C From 2002 to 2005, the budget increased

or about 10%. This

option is not correct.

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. The sales figures increased 1% from 2003 to 2004.

B. The largest increase in annual sales occurred from 2003 to 2004.

C. The sales figures decreased about 33% from 2004 to 2005.

D. The sales figures decreased and then increased.

The table shows the annual sales figures for a popular retail store for the past four years. Which statement is supported by the table?

Five-Minute Check (over Lesson 7-6)

Main Idea and Vocabulary

California Standards

Example 1: Find the Total Cost

Example 2: Find the Sale Price

Example 3: Find the Original Price

• sales tax

• discount

• Solve problems involving sales tax and discount.

Standard 6NS1.4 Calculate given percentages of quantities and solve problems involving discounts at sales, interest earned, and tips.

Find the Total Cost

GOLF A set of golf balls sells for $20, and the sales tax is 5.75%. What is the total cost of the set?

Method 1 Add sales tax to the regular price.

First, find the sales tax.

5.75% of $20 = 0.0575 ● 20 Write 5.75% as a decimal.

= 1.15 The sales tax is $1.15.

Next, add the sales tax to the regular price.

1.15 + 20 = 21.15

A shirt costs $25. The sales tax is 7%. What is the total cost of the shirt?

7% = 0.07

0.07 · $25 = $1.75 Tax

$1.75 + $25 = $26.75 Total price with tax

So, the price of the shirt including tax is $26.75.

A calculator costs $90. The sales tax is 4.25%. What is the total cost of the calculator?

4.25% = 0.0425

0.0425

·$90 = 3.825 ≈ $3.83 Tax

$3.83 + $90 = $93.83 Total price

So, the price of the calculator including tax is $93.83.

A watch costs $115.48 The sales tax is 6%. What is the total cost of the watch?

6% = 0.06

0.06 · $115.48 = 6.9288 ≈$6.93 Tax

$6.93 + $115.48 = $122.41 Total price with tax

So, the price of the watch including tax is $122.41.

A. A

B. B

C. C

D. D0% 0%0%0%

A. $2.45

B. $24.50

C. $37.45

D. $59.50

BOOKS A set of three paperback books sells for $35 and the sales tax is 7%. What is the total cost of the set?

Find the Sale Price

OUTERWEAR Whitney wants to buy a new coat that has a regular price of $185. This weekend, the coat is on sale at a 33% discount. What is the sale price of the coat?

Method 1 Subtract the discount from the regular price.

First, find the amount of the discount.

33% of $185 = 0.33 ● $185 Write 33% as a decimal.

= $61.05 The discount is $61.05.

Next, subtract the discount from the regular price.

So, the sale price is $185 – $61.05 or $123.95.

A belt costs $35. The discount is 40%. What is the total cost of the belt?

40% = 0.40

0.40 · $35 = $14 Discount

$35 – $14 = $21 Total price after discount

So, the price of the belt including discount is $21.

A pair of jeans costs $39. The discount is 25%. What is the total cost of the jeans?

25% = 0.25

0.25 · $39 = $9.75 Discount

$39.00 - $9.75 = $29.25. Total price after discount

So, the price of the shirt including discount is $29.25.

A sweatshirt costs $42. The sales tax is 5 What is the total cost of the sweatshirt?

5.5% = 0.055

0.055

·$42 = $2.31 Tax

$2.31 + $42 = $44.31 Total price with tax

%.

So, the price of the sweatshirt on sale is $44.31.

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. $35

B. $210

C. $171.50

D. $140

ELECTRONICS Alex wants to buy a DVD player that has a regular price of $175. This weekend, the DVD player is on sale at a 20% discount. What is the sale price of the DVD player?

A guitar is on sale at 40% off. The sale price is $179.94. What is the original price?

The sale price is 60% (100% – 40%) of the original price.

n

179.94Part

Whole 100

60=179.94 100· = 60 ·n

17994 = 60n60 60299.90 n=

17994 = 60n

A calendar is on sale at 75% off. The sale price is $2.25. What is the original price?The sale price is 25% (100% – 75%) of the original price.

n

2.25Part

Whole 100

25=2.25 100· = 25 ·n

225 = 25n25 259 n=

225 = 25n

A calendar is on sale at 30% off. The sale price is $126. What is the original price?The sale price is 70% (100% – 30%) of the original price.

n

126Part

Whole 100

70=126 100· = 70 ·n

12600 = 70n70 70180 n=

12600 = 70n

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. $375

B. $366.56

C. $270.94

D. $431

FURNITURE A rocking chair is on sale at 15% off. If the sale price is $318.75, what is the original price?

Five-Minute Check (over Lesson 7-7)

Main Idea and Vocabulary

California Standards

Example 1: Find Interest Earned

Example 2: Find Interest Earned

Example 3: Find Interest Paid on a Loan

Example 4: Find Total Paid on a Credit Card

• simple interest

• principal

• Solve problems involving simple interest.

Standard 6NS1.4 Calculate given percentages of quantities and solve problems involving discounts at sales, interest earned, and tips.

Find Interest Earned

SAVINGS Brandon found a bank offering a certificate of deposit that pays 4% simple interest. He has $1,500 to invest. How much interest will he earn in 3 years?

I = prt Formula for simple interest

I = 1,500 ● 0.04 ● 3 Replace p with $1,500, r with 0.04, and t with 3.

I = 180 Simplify.Answer: Brandon will earn $180 in interest in 3 years.

Simple Interest: The amount paid or earned for the use of money.

I = p · r· t

Principal: The amount of money deposited or borrowed.

Annual interest rate written as a

decimal.Amount of time (IN YEARS) that

money is deposited or borrowed.

Interest

Expressing Months in years

Find the simple interest earned in a savings account where $136 is deposited for 2 years if the interest rate is 7.5% per year.

I = $136 · 0.075 · 2

I = $20.40

I = prt

The interest is $20.40.

7.5% = 0.075

Find the simple interest for $600 invested at 8.5% for 6 months.

I = $600 · 0.085 · 0.5

I = $25.50

I = prt

The interest is $25.50.

8.5% = 0.085

6 months = years

Find the simple interest for $300 invested at 6.75% for 1 ¾ years.

I = $300 · 0.0675 · 1.75

I = 35.4375 ≈ $35.44

I = prt

The interest is $35.44.

6.75% = 0.0675

1 ¾ years = 1.75 years

If Robin invests $2500 in a savings account, that yields 4% interest what will the account be worth after 2 years?

I = $2500 · 0.04 · 2

I = $200 Interest

I = prt

$2500 + $200 = $2700 Total money in the account

4% = 0.04

Ellen invests $2500 at an interest rate of 5%. In how many years will she have $3000?

500 = $2500 · 0.05 · t

500 = 125t

I = prt

t = 4. In 4 years she will have $3000.

5% = 0.05

She would have to earn $500 in interest to have $3000.

500 = 125t125 125

The average cost for a vacation is $1050. If a family borrows money for the vacation at an interest rate of 11.9% for 6 months, what is the total cost of the vacation including the interest on the loan?

I = $1050 · 0.119 · 0.5

I = 62.475 ≈ $62.48 Interest

I = prt

$1050 + $62.48 = $1112.48 Total cost of the vacation

11.9% = 0.119

6 months = 0.5 years

A. A

B. B

C. C

D. D0% 0%0%0%

A. $60

B. $300

C. $450

D. $6000

SAVINGS Cheryl opens a savings account that pays 5% simple interest. She deposits $600. How much interest will she earn in 2 years?

Find Interest Earned

SAVINGS Brandon found a bank offering a certificate of deposit that pays 4% simple interest. He has $1,500 to invest. How much interest will he earn in 30 months?

Write the time as years.

Answer: Brandon will earn $150 in interest in 30 months.

I = prt Formula for simple interest

I = 1,500 ● 0.04 ● 2.5 p = $1,500, r = 0.04, t = 2.5

I = 150 Simplify.

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. $28

B. $280

C. $2,800

D. $3,360

SAVINGS Micah opens a savings account that pays 4% simple interest. He deposits $2,000. How much interest will he earn in 42 months?

Find Interest Paid on a Loan

LOANS Laura borrowed $2,000 from her credit union to buy a computer. The interest rate is 9% per year. How much interest will she pay if it takes 8 months to repay the loan?

I = prt Formula for simple interest

Answer: Laura will pay $120 in interest in 8 months.

I = 120 Simplify.

I = 2,000 ● 0.09 ● Replace p with $2,000, r with

0.09, and t with

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. $225

B. $1,500

C. $2,250

D. $25,000

LOANS Juan borrowed $7,500 from the bank to purchase a used car. The interest rate is 15% per year. How much interest will he pay if it takes 2 years to repay the loan?

CREDIT CARDS Alma charged a $30 handbag on her credit card with an interest rate of 8%. How much money will she owe if she has no other charges on the card, and she does not pay off the balance at the end of the month?

Answer: So, the total amount owed would be $30 + $0.20 or $30.20.

Find Total Paid on a Credit Card

I = prt Formula for simple interest

I = 0.20 Simplify.

I = 30 ● 0.08 ● Replace p with $30, r with 0.08,

and t with

A. A

B. B

C. C

D. D0% 0%0%0%

A. $45

B. $60.45

C. $64.05

D. $65.95

CREDIT CARDS Curtis charged a $60 power tool on his credit card with an interest rate of 9%. How much money will he owe if he has no other charges on the card and he does not pay off the balance at the end of the month?

Five-Minute Checks

Image Bank

Math Tools

Percent of a Number

Percent of Change

Lesson 7-1 (over Chapter 6)

Lesson 7-2 (over Lesson 7-1)

Lesson 7-3 (over Lesson 7-2)

Lesson 7-4 (over Lesson 7-3)

Lesson 7-5 (over Lesson 7-4)

Lesson 7-6 (over Lesson 7-5)

Lesson 7-7 (over Lesson 7-6)

Lesson 7-8 (over Lesson 7-7)

To use the images that are on the following three slides in your own presentation:

1. Exit this presentation.

2. Open a chapter presentation using a full installation of Microsoft® PowerPoint® in editing mode and scroll to the Image Bank slides.

3. Select an image, copy it, and paste it into your presentation.

A. A

B. B

C. C

D. D

0% 0%0%0%

Write the ratio 35 meters to 1000 centimeters as a fraction in simplest form.

(over Chapter 6)

A.

B.

C.

D.

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. $4.72 per ounce; $4.52 per ounce; $3.39 for 16 ounces is the better deal.

B. $4.52 per ounce; $4.72 per ounce; $3.98 for 18 ounces is the better deal.

C. $0.22 per ounce; $0.21 per ounce; $3.98 for 18 ounces is the better deal.

D. $0.22 per ounce; $0.21 per ounce; $3.39 for 16 ounces is the better deal.

One box of cereal cost $3.98 and weighs 18 ounces, and another box costs $3.39 and weighs 16 ounces. What are the unit prices for each box of cereal? Which is the better deal?

(over Chapter 6)

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

If you were making a scale drawing of a building that is 500 feet tall, how large would the drawing be with a scale of 1 inch = 35 feet? Write the answer as a fraction.

(over Chapter 6)

A.

B.

C.

D.

A. A

B. B

C. C

D. D

0% 0%0%0%

Write 240% as a decimal and a mixed number or fraction in simplest form.

(over Chapter 6)

A.

B.

C.

D.

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

10 c = __ pt

(over Chapter 6)

A. 20

B.

C. 5

D. 40

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. rate

B. scale

C. unit rate

D. base

Choose the term which describes a ratio where the denominator must be 1 when it is in simplest form.

(over Chapter 6)

A. A

B. B

C. C

D. D

0% 0%0%0%

A. 36

B. 74

C. 99

D. 275

What is 165% of 60? Round to the nearest tenth if necessary.

(over Lesson 7-1)

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. 77.33

B. 174.75

C. 194.27

D. 310.67

What number is 233% of 75?

(over Lesson 7-1)

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. 187.5

B. 53.3

C. 43.2

D. 42.3

48% of 90 is what number?

(over Lesson 7-1)

A. A

B. B

C. C

D. D

0% 0%0%0%

A. $18

B. $73

C. $83

D. $292

Find 20% of $365.

(over Lesson 7-1)

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. 173.25

B. 169.63

C. 157.14

D. 63.63

What number is 165% of 105?

(over Lesson 7-1)

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. 11

B. 25

C. 33

D. 44

Tanya earns a perfect score 25 percent of the time when she performs her gymnastics routine in front of a panel of judges. If she performs 44 times in a season, how many times will she not receive a perfect score?

(over Lesson 7-1)

A. A

B. B

C. C

D. D

0% 0%0%0%

A. 2,000%

B. 31.3%

C. 20%

D. 3.2%

What percent of 80 is 25? Round to the nearest tenth if necessary.

(over Lesson 7-2)

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. 24

B. 50

C. 110

D. 2,400

What number is 30% of 80? Round to the nearest tenth if necessary.

(over Lesson 7-2)

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. 10

B. 12

C. 75

D. 1,200

30 is 40% of what number? Round to the nearest tenth if necessary.

(over Lesson 7-2)

A. A

B. B

C. C

D. D

0% 0%0%0%

A. 0.14%

B. 14.3%

C. 252%

D. 700%

$6 is what percent of $42? Round to the nearest tenth if necessary.

(over Lesson 7-2)

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. 0.008

B. 0.8

C. 8

D. 20

What number is 0.2% of 4? Round to the nearest tenth if necessary.

(over Lesson 7-2)

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. $7.20

B. $16

C. $36

D. $80

Joseph saves 30% of his allowance each week. If he saves $24 in 5 weeks, how much allowance does Joseph receive each week?

(over Lesson 7-2)

A. A

B. B

C. C

D. D0% 0%0%0%

A. 13

B. 15

C. 16

D. 17

Estimate 48% of 30 by using fractions.

(over Lesson 7-3)

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. 22

B. 25

C. 28

D. 30

Estimate 8.5% of 278 by using fractions.

(over Lesson 7-3)

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. 49

B. 50

C. 54

D. 55

Estimate 112% of 49 by using 10%.

(over Lesson 7-3)

A. A

B. B

C. C

D. D0% 0%0%0%

A. 60

B. 64

C. 65

D. 68

Estimate 83% of 79 by using 10%.

(over Lesson 7-3)

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. 35

B. 34

C. 28

D. 27

Twenty-two percent of the seventh-grade class at Santa Ana Middle School have blue eyes. If the seventh-grade class has 139 students, about how many have blue eyes?

(over Lesson 7-3)

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. 18

B. 23

C. 128

D. 234

Estimate 128% of 179.

(over Lesson 7-3)

A. A

B. B

C. C

D. D

0% 0%0%0%

A. 38 = n ● 320; 11.9%

B. 38 = n ● 320; 8.4%

C. 320 = 38 ● n; 8.4%

D. 320 = 38 ● n; 11.9%

Write an equation for the problem. Then solve. Round to the nearest tenth if necessary. 38 is what percent of 320?

(over Lesson 7-4)

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. 24 ● n = 72; 3

B. 0.24 ● 72 = n; 18

C. 0.24 ● n = 72; 33

D. 0.24 ● n = 72; 300

Write an equation for the problem. Then solve. Round to the nearest tenth if necessary. 24% of what number is 72?

(over Lesson 7-4)

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. 0.43 ● n = 128; 29.7

B. 0.43 ● 128 = n; 29.7

C. 0.43 ● 128 = n; 55.0

D. 128 ● n = 0.43; 55.0

Write an equation for the problem. Then solve. Round to the nearest tenth if necessary. Find 43% of 128.

(over Lesson 7-4)

A. A

B. B

C. C

D. D

0% 0%0%0%

A. n ● 28 = 9; 32.1%

B. 0.9 ● n = 28; 32.1%

C. 0.9 ● n = 28; 31.1%

D. n ● 28 = 9; 25.2%

Write an equation for the problem. Then solve. Round to the nearest tenth if necessary. What percent of 28 is 9?

(over Lesson 7-4)

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. 13 ● 1,292.42 = n; $168.01

B. 0.13 ● 1,292.42 = n; $168.01

C. 13 ● 1,292.42 = n; $99.41

D. 0.13 ● 1,292.42 = n; $99.41

Thirteen percent of the profits from Kendall’s business are donated to charities. Write and solve an equation to find out how much Kendall donates if her profits are $1,292.42.

(over Lesson 7-4)

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. 17.7%

B. 17.3%

C. 16.7%

D. 16.3%

17 is what percent of 104?

(over Lesson 7-4)

A. A

B. B

C. C

D. D

0% 0%0%0%

A. 3 hours

B. 5 hours

C. 7 hours

D. 8 hours

If the speed limit is 65 miles per hour, what is a reasonable amount of time it will take the Blackwell’s to travel 300 miles?

(over Lesson 7-5)

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. 35

B. 40

C. 50

D. 25

There are 400 boys at Oak Middle School and 9% play football. What is a reasonable number of boys that play football?

(over Lesson 7-5)

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. $11.00

B. $5.00

C. $7.00

D. $12.00

Suppose you are going to dinner and a movie with a friend. If you spend $18 and the movie is 62% of the cost, what is a reasonable cost for dinner?

(over Lesson 7-5)

A. A

B. B

C. C

D. D

0% 0%0%0%

A. 2 quarters, 2 dimes, 1 nickel, 1 penny

B. 3 quarters, 3 nickels

C. 3 quarters, 2 nickels, 1 penny

D. 4 dimes, 2 pennies

Lisa has 6 coins that total $0.86. What are the coins?

(over Lesson 7-5)

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. 4

B. 5

C. 7

D. 9

A number is multiplied by 13. Then 5 is subtracted from the product. The result is 60. What is the number?

(over Lesson 7-5)

A. A

B. B

C. C

D. D

0% 0%0%0%

A. 60% increase

B. 60% decrease

C. 40% increase

D. 40% decrease

Find the percent of change. Round to the nearest whole percent if necessary. State whether the percent of change is an increase or decrease. original: 50; new: 80

(over Lesson 7-6)

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. 31% increase

B. 31% decrease

C. 45% increase

D. 45% decrease

Find the percent of change. Round to the nearest whole percent, if necessary. State whether the percent of change is an increase or decrease. original: 138; new: 200

(over Lesson 7-6)

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. 32% increase

B. 32% decrease

C. 24% increase

D. 24% decrease

Find the percent of change. Round to the nearest whole percent if necessary. State whether the percent of change is an increase or decrease. original: $21.50; new: $16.25

(over Lesson 7-6)

A. A

B. B

C. C

D. D

0% 0%0%0%

A. 741% increase

B. 741% decrease

C. 88% increase

D. 88% decrease

Find the percent of change. Round to the nearest whole percent if necessary. State whether the percent of change is an increase or decrease. original: 17; new: 143

(over Lesson 7-6)

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. 36%

B. 44%

C. 56%

D. 67%

Natalie’s kitten weighed 2.7 pounds when she bought it. Now it weighs 4.2 pounds. What is the percent of increase in the kitten’s weight?

(over Lesson 7-6)

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. 35% increase

B. 35% decrease

C. 7.2% increase

D. 7.2% decrease

If the first movie release by a film company this year made $20.4 million dollars at the box office, and the second movie made $13.2 million, what was the percent of change in the film company’s revenues.

(over Lesson 7-6)

A. A

B. B

C. C

D. D

0% 0%0%0%

A. $36

B. $84

C. $150

D. $156

Find the total cost or sale price to the nearest cent. $120 jacket; 30% discount

(over Lesson 7-7)

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. $12,915

B. $12,685

C. $11,915

D. $11,685

Find the total cost or sale price to the nearest cent. $12,300 car; 5% sales tax

(over Lesson 7-7)

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. $10.98

B. $11.98

C. $12.02

D. $13.02

Find the total cost or sale price to the nearest cent. $12 book; 8.5% sales tax

(over Lesson 8-8)

A. A

B. B

C. C

D. D

0% 0%0%0%

A. 85%

B. 60%

C. 40%

D. 15%

Find the percent of discount to the nearest percent. regular priced meal: $32.50; employee meal: $13

(over Lesson 7-7)

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. $6.49 per shirt; 50% discount

B. $6.94 per shirt; 50% discount

C. $8.66 per shirt; 66% discount

D. $8.66 per shirt; 33% discount

A shirt at the store is advertised "Buy 2, Get 1 Free." If the original price of the shirt is $12.99 and you take advantage of the special offer, what is the price you would pay per shirt, and what percent is the discount from the original price?

(over Lesson 7-7)

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. $46.50

B. $108.50

C. $114.47

D. $190.42

A hotel room costs $155 per night. What is the total cost with a 30% discount and 5.5% sales tax?

(over Lesson 7-7)

This slide is intentionally blank.