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7-10 Using Percents7-10 Using Percents

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Warm UpWarm Up

Lesson PresentationLesson Presentation

Problem of the DayProblem of the Day

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7-10 Using Percents

Warm UpFind the percent of each number.

1. 75% of 300

2. 93% of 56

3. 32% of 128

4. 9% of 60

225

52.08

40.965.4

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7-10 Using Percents

Problem of the Day

A chessboard is 8 squares wide by 8 squares long. Each player has 8 pawns, 1 king, and 7 other pieces. At the start of a game, all the pieces are on the board, 1 piece per square. What percent of the total number of squares have a chess piece?

50%

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7-10 Using Percents

Learn to solve percent problems that involve discounts, tips, and sales tax.

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7-10 Using Percents

Vocabulary

discounttipsales tax

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7-10 Using Percents

Common Uses of Percents

Discounts A discount is an amount that is subtracted from the regular price of an item. discount = price • discount rate total cost = price – discount

Tips A tip is an amount added to a bill for service. tip = bill • tip rate total cost = bill + tip

Sales tax Sales tax is an amount added to the price of an item.

sales tax = price • sales tax rate total cost = price + sales tax

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7-10 Using Percents

Additional Example 1: Finding Discounts A clothing store is having a 10% off sale. If Angela wants to buy a sweater whose regular price is $19.95, about how much will she pay for the sweater after the discount?

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7-10 Using Percents

Commission - Is an amount earned on top of ( extra) than your regular pay.

Commission = commission rate x amount soldTotal pay = original pay + commission earned

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7-10 Using Percents

Check It Out: Example 1

A fishing store is having a 10% off sale. If Gerald wants to buy a fishing pole whose regular price is $39.95, about how much will he pay for the pole after the discount?

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7-10 Using Percents

When estimating percents, use percents that you can calculate mentally.

• You can find 10% of a number by moving the decimal point one place to the left.

• You can find 1% of a number by moving the decimal point two places to the left.

• You can find 5% of a number by finding one-half of 10% of the number.

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7-10 Using Percents

Additional Example 2: Finding Tips

Ben’s dinner bill is $7.85. He wants to leave a tip that is 15% of the bill. About how much should his tip be?

.

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7-10 Using Percents

Check It Out: Example 2

Lita’s dinner bill is $11.95. She wants to leave a tip that is 15% of the bill. How much should her tip be?

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7-10 Using Percents

Additional Example 3: Finding Sales Tax Ann is buying a dog bed for $29.75. The sales tax rate is 7%. How much will the total cost of the dog bed be?

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7-10 Using Percents

Check It Out: Example 3 Erik is buying a blanket for $19.83. The sales tax rate is 8%. How much will the total cost of the blanket be?

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7-10 Using Percents

Lesson Quiz

1. Sean’s new jeans are priced at $29.97, but the sale sign reads, “Take 15% off.” How much will the jeans cost after the discount?

2. The bill for a family dinner comes to $56.78. About how much would a 20% tip be?

3. The price on a book is $12.99. If sales tax is 4%, how much will its total cost be?

4. Megan wants a new bike. She is happy to see a sign that reads, “All bikes 10% off.” If the original price of the bike was $159.90 and sales tax is 6%, How much will the total cost of the bike be?

About $11.50