7th Grade Math

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Applying Percents

PART A B C DE F

Multi-Part

Lesson 3

GLE 0706.2.4

Use ratios, rates and

percents to solve single-

and multi-step problems

in various contexts. Also

addresses GLE 0706.1.7.

Main Idea

Solve problems

involving sales tax

and tips.

Vocabulary

sales tax

tip

gratuity

Sales Tax and Tips

KAYAKS Alonso plans to

buy a new kayak that costs $1,849.

He lives in a county where there

is a 7.5% sales tax.

1. Calculate the sales tax by
   finding 7.5% of $1,849. Round
   to the nearest cent.


2. What will be the total cost including the sales tax?


3. Multiply 1.075 and 1,849. How does the result compare to your
   answer in Exercise 2?

Sales tax is an additional amount of money charged on items that people

buy. The total cost of an item is the regular price plus the sales tax.

Find the Total Cost

ELECTRONICS A DVD player costs $140 and the sales tax is 5.75%.

What is the total cost of the DVD player?

Method 2 Add the percent of tax to 100%.

100% + 5.75% = 105.75% Add the percent of tax to 100%.

The total cost is 105.75% of the regular price.

105.75% of $140 = 1.0575 × $140 Write 105.75% as a decimal.

= $148.05 Multiply.

Method 1 Add sales tax to the regular price.

First, find the sales tax.

5.75% of $140 = 0.0575 × 140 Write 5.75% as a decimal.

= 8.05 The sales tax is $8.05.

Next, add the sales tax to the regular price.

$8.05 + $140 = $148.05

The total cost of the DVD player is $148.05.

a. CLOTHES What is the total cost of a sweatshirt if the regular

price is $42 and the sales tax is 5 _^12 %?

buya

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Lesson 3C Applying Percents 351

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