with discounts sales tax and tips learning about percent

With DiscountsSales Taxand Tips

LEARNING ABOUT PERCENT

Fractions, decimals, and percent are used everywhere all around us. In this tutorial you will practice calculating discounts and sale prices and learn strategies for finding a tip.

HOW TO USE THIS TUTORIALWhat is a

StAIR?

A StAIR activity is a stand alone instructional

resource. This StAIR was created

for students to learn more about finding

the percent of a number in two real life situations: sales

tax and tipping. After viewing the instructional parts of the power point, students will work through several

practice problems to demonstrate

their understanding of the skill.

Follow the directions on each page to learn more about how to find the percent of a

number.

HOME PAGE

Review

Lesson

Practice

Start with the review, then

move on to the lesson. When

you’re done, try the practice problems.

When you are changing a

percent to a decimal, divide the percent by

100 and drop the percent sign. Shortcut - just

move the decimal two places to the left! Look at the table to see how

it’s done.

REVIEWRemember … fractions, decimals, and percents are related. You can easily change from a decimal to a percent or from a percent to a decimal.

Now, it’s your turn …

Example 1: Change 32% to a decimal 0.32

Example 2: Write 153% as a decimal 1.53

REVIEW

ANSWER

ANSWER

When you are changing a

decimal to a percent, multiply

the number by 100 and add a percent sign.

Shortcut - move the decimal two

places to the right. Here’s

what that looks like.

REVIEW

Let’s try these problems…

Example 1: Change 0.86 to a percent 86%

Example 2: Write 0.23 as a percent 23%

REVIEW

ANSWER

ANSWER

GREAT WORK

Now you’re ready for the

! ! !

Discounts!

It’s important to know how to work with percents when you are shopping so you can find the cost of sale items and know what to leave for a tip when you are provided a service.

Let’s fi rst talk about

LESSONPercent

Percent is represented with the % symbol. It is a ratio that means out of 100 or “per hundred.”

15% = 15/100 = 0.15

25% = 25/100 = 0.25 SALE

S!

Good news! The cell phone you’ve always wanted has just gone on sale. The regular price of the phone is $128 and it’s 20% off.

Regular Price

The price of an item before a discount. This is sometimes referred to as the original price.

Discount

A discount is calculated as a percent of decrease.

Sale Price

The sale price is the amount paid after a discount is applied.

EXAMPLE 1 DISCOUNTS

You can calculate the discount by finding 20% of $128.

Click the arrow to find out how.

STEPS

1 2 8

x 0 2

1. 20% = 0.20

2. 128 x 0.20 =

3. $128.00 –$ 25.60 =

1. Change the percent to a decimal.

2. Multiply this decimal by the regular price. Don’t forget to place the decimal in the right place in your answer.3. Now to find the sale price, subtract the discount from the regular price.

$ 102.40

6

1

52

$25.60

Ready for another example?

EXAMPLE 1 DISCOUNTS

In a catalog you find a telescope on sale for 35% off. The original price is $180. How much is the sale price?

Regular Price


Discount


Sale Price


EXAMPLE 2 DISCOUNTS

You can calculate the discount by finding 35% of $180.


STEPS

1 8 0

x 0 3 5

1. 35% = 0.35

2. 180 x 0.35 =

3. $180.00 –$ 63.00 =



$ 117.00

0

4

09

$63.00

Let’s try one more.

EXAMPLE 2 DISCOUNTS

004

2

5+

0036

1

On the clearance counter you find a calendar marked 75% off. The regular price of the calendar was $9.00. What is the sales price?

Regular Price


Discount


Sale Price


EXAMPLE 3 DISCOUNTS

You can calculate the discount by finding 75% of $9.00.


STEPS

0 7 5

x 9

1. 75% = 0.75

2. 9 x 0.75 =

3. $9.00 –$ 6.75 =



$ 2.25

5

4

76

$6.75

Not too hard, is it? Now, we can’tforget about sales tax! So click the arrow to learn how that’s calculated.

EXAMPLE 3 DISCOUNTS

6

To find the amount of sales tax you need to:

Sales Tax

Sales tax varies from state to state. To determine the amount of sales tax on an item you must first know the tax rate in your state. In the state of Michigan sales tax is 6%. Sales tax is added to the price of an item at the point of purchase.

SALES TAX


For more information and examples about sales taxclick .HERE

2. Multiply that by the cost of your item.

3. Finally, add that amount to the cost of your item.

http://www.studyzone.org/mtestprep/math8/e/salestax6l.cfm

In our cell phone example we found the sale price to be $102.40

SALES TAX EXAMPLE 11. Change the tax rate to a decimal.6% = 0.062. Multiply 0.06 by the cost of your item. Round your answer to the nearest hundredth.3. Add that amount to your original cost.

0.06 x 102.40 = 6.144 This should be rounded to $6.14

STEP 1

STEP 2

STEP 3

6% = 0.06

$102.40 + $6.14 =

$108.54

This is the ACTUAL amount you would pay for the cell phone.

In the telescope example we found the sale price to be $117.00


0.06 x 117 = 7.02

STEP 1

STEP 2

STEP 3

6% = 0.06

$117 + $7.02 = $124.02

This is the ACTUAL amount you would pay for the telescope.

The calendar cost was $2.25


0.06 x 2.25 = 0.135This can be rounded to 0.14

STEP 1

STEP 2

STEP 3

6% = 0.06

$2.25 + $0.14= $2.39

This is the ACTUAL amount you would pay for the calendar.

FOR MORE INSTRUCTION

Click Here

http://www.studyzone.org/mtestprep/math8/g/perapplisalepricel.cfm

It’s important to be able to fi gure out a tip quickly. There are many circumstances where this is needed …

TIPPINGTips

A tip or gratuity is a small amount of money left in exchange for a service. Tips are calculated as a percent of a price just like sales tax.

for servers at restaurants

for the person who cuts your hair

for the valet who retrieves your car or for the taxi cab driver

TIPPINGTips

A tip or gratuity is a small amount of money left in exchange for a service. Tips are calculated as a percent of a price just like sales tax.

To determine the tip, you need to change the percent to a decimal and multiply by the cost of the service.

Here’s how it’s done …

Click for a shortcut.

It is generally accepted that a tip should be between 15% and 20% of the service provided.The rule of thumb is 15% for adequate service and 20% for exceptional service.

So, if your bill at the diner came to $23.50 and you had exceptional service you would want to leave a 20% tip.

20% = 0.2

0.2 x 23.50 = $4.70

HERE

You would leave $4.70

A customer wants to leave a 15% tip on a bill for $18.60 at a Chinese restaurant. Find out how much the customer should leave.

TIPPING EXAMPLE 1Step 1

Change the percent to a decimal.

0.15 x 18.60 = 2.79

STEP 3

If needed, round to the nearest hundredth.

STEP 2

Multiply the percent by the total bill.

15% = 0.15Click HERE

for a reminder

about using mental math

$2.79 is 15% of $18.60

A customer decides to leave a 20% tip for his dog groomer. The cost for the service was $35.00. What is the tip the customer leaves?



0.20 x 35 = 7

STEP 3


STEP 2


20% = 0.2Click HERE

for a reminder

about using mental math

$7.00 is 20% of $35.00

Rachel gets a ride in a taxi from the airport. The cab fare came to $27 and she decided to tip the driver 18%. How much money did she give to the driver?



0.18 x 27 = 4.86STEP 3


STEP 2


18% = 0.18

She tipped the driver $4.86

Click on the attached video link to review what we learned about solving percent problems with taxes and tips.

VIDEO

http://www.youtube.com/watch?v=s11SiS0tVjI

PRACTICE

Discount Problems

Gratuity Problems

Now, you’re ready to

practice some problems on your own.

DISCOUNT PROBLEM 1

Max found the bike that he’s wanted for a long time on sale at 25% off. The original price of the bike was $210. What is the price with the discount?

$195.30 $142.50 $178.00 $157.50

You Got It!

Way to Go

WRONG ANSWER

Do you need ?

YES

NO

HERE’S WHAT TO DO

STEP 1Change the percent to a decimal.

Multiply this decimal by the regular price. Don’t forget to place the decimal in the right place in your answer.

Now to find the sale price, subtract the discount from the regular price.

STEP 2

STEP 3

25% = 0.25

0.25 x 210 =

210.00 − 52.50 =

Back to the

Problem

DISCOUNT PROBLEM 2

The bakery sells a dozen cupcakes for $29. To celebrate their one year anniversary the owner is selling all cupcakes for 20% off the regular price. How much will it cost to buy a dozen cupcakes on this day?

$23.20 $24.80 $28.52 $23.00

Try AgainSorry

Do you need ?

YES

NO

HERE’S WHAT TO DO




STEP 2

STEP 3

20% = 0.2

0.2 x 29 =

29.00 − 5.80 =

Back to the

Problem

The answer is $23.20

YES!

DISCOUNT PROBLEM 3

A necklace regularly sells for $18.00. The store advertises a 15% discount. What is the sale price of the necklace in dollars?

$15.60 $16.70 $16.20 $15.30

RIGHT ON

Good Work

WRONG ANSWER

Do you need ?

YES

NO

Check your work !

HERE’S WHAT TO DO




STEP 2

STEP 3

15% = 0.15

0.15 x 18 =

18.00 − 2.70 =

Back to the

Problem

DISCOUNT PROBLEM 4

A new radio is priced at $30. The store has an end-of-year sale and all their items are 30% off. What is the sale price of the radio?

$27.00 $21.00 $24.00 $9.00

You Got It!

Way to Go

WRONG ANSWER

Do you need ?

YES

NO

TRY AGAIN

HERE’S WHAT TO DO




STEP 2

STEP 3

30% = 0.3

0.3 x 30 =

30.00 − 9.00 =

Back to the

Problem

DISCOUNT PROBLEM 5

A chair that costs $210 was reduced by 40% for a one-day sale. After the sale, the sale price was increased by 40%. What is the price of the chair?

$176.40 $185.30 $205.50 $210.00

You Got It!

Way to Go

WRONG ANSWER

Do you need ?

YES

NO

Check your work !

HERE’S WHAT TO DO

STEP 1

Change the percent to a decimal. 40% = 0.4

Multiply this decimal by the regular price. Don’t forget to place the decimal in the right place in your answer. 0.4 x 210 = ________

Now to find the sale price, subtract the discount from the regular price. 210.00 – 84.00 = _________

STEP 2

STEP 3

Back to the

Problem

STEP 4

Now you have to find 40% of that sale price. So, $126 x 0.4 = _______. Then, add that amount to $126.

With problems involving discounts

FOR MORE PRACTICE

Click Here

http://www.mathplayground.com/percent_shopping.html

GRATUITY PROBLEM 1

The cost of Ken’s car wash was $23.95. If he wants to give his detailer a 15% tip, about how much of a tip should he leave?

$2.40 $3.60 $4.60 $4.80

You Got It!

Way to Go

WRONG ANSWER

Do you need ?

YES

NO

HERE’S WHAT TO DO



Round your answer to the nearest hundredth and you get $3.59. Since this question asks about how much would you tip, you would give $3.60.

STEP 2

STEP 3

15% = 0.15

0.15 x 23.95 =

Back to the

Problem

GRATUITY PROBLEM 2

Constance got a manicure at the beauty shop. The cost for the manicure was $25.50. She left a 15% tip. How much money did she tip?

$1.70 $3.83 $5.10 $38.25

Try AgainSorry

Do you need ?

YES

NO

HERE’S WHAT TO DO



Now, round your answer to the nearest hundredth.

STEP 2

STEP 3

15% = 0.15

0.15 x 25.50 =

$3.83

Back to the

Problem

The answer is $3.83

YES!

GRATUITY PROBLEM 3

At a diner, Ruthie orders soup, salad, and a drink that comes to $7. Find the total cost of the meal if she leaves an 18% tip.

$8.18 $8.26 $1.26 $7.85

RIGHT ON

Good Work

WRONG ANSWER

Do you need ?

YES

NO

Check your work !

HERE’S WHAT TO DO



Now to find the TOTAL COST of the meal you need to add the tip amount to the cost of food.

STEP 2

STEP 3

18% = 0.18

0.18 x 7 =

1.26 + 7.00 =

Back to the

Problem

GRATUITY PROBLEM 4

A cab ride home cost 16.40. Billy gave the driver a 20% tip for his great service. How much money did Billy give the cab driver?

$32.80 $1.64 $3.86 $3.28

You Got It!

Way to Go

WRONG ANSWER

Do you need ?

YES

NO

TRY AGAIN

HERE’S WHAT TO DO



STEP 2

20% = 0.2

0.2 x 16.40 =

Back to the

Problem

GRATUITY PROBLEM 5

You and five friends go to lunch. You plan to split the bill evenly, and you plan to leave a 20% tip. The bill comes to $55.50. How much will each person pay for the meal?

$8.88 $11.10 $13.32 $12.65

You Got It!

Way to Go

WRONG ANSWER

Do you need ?

YES

NO

Check your work !

HERE’S WHAT TO DO

STEP 1

Change the percent to a decimal. 20% = 0.2

Multiply this decimal by the regular price. Don’t forget to place the decimal in the right place in your answer. 0.2 x 55.50 = ________

Now to find the total price, add the tip to the bill. 11.10 + 55.50 = _________

STEP 2

STEP 3

Back to the

Problem

STEP 4

To find out how much each person should contribute, divide that total by 5. 66.60 ÷ 5 = __________

Easy! Move the decimal one place to the left.

SHORTCUT

Use Mental Math

1. Find 10 % of your number by dividing the total by 10.

2. To find 20% just double that number since 20 % = 10% + 10%

If you are trying to figure out 15%, you just need to remember that15% = 10% + 5%. If your bill was $34.00, 10% is $3.40, you can take half of that number to find 5% . Half of $3.40 is $1.70 ( 3.40 ÷ 2 = 1.70). Now, just add this together. 3.40 + 1.70 = $5.10

That’s a great idea!

Easy! Move the decimal

one place to the left.

SHORTCUT

Use Mental Math


2. Remember 15% = 10% + 5%, so let’s find 5% now

Moving the decimal one place to the left for $18.60gives us $1.86

5% is half of 10%. So, divide $1.86 in half and you get $0.93

3. Now, you just need to add these together.

$0.93 + $1.86 = $2.79$2.79 is a 15% tip on $18.60

Easy! Move the decimal

one place to the left.

SHORTCUT

Use Mental Math


2. Since 20% = 10% + 10%, just double the answer you got in step 1.

Moving the decimal one place to the left for $35.00gives us $3.50

$3.50 x 2 = $7.00

CONGRATULATIONS!

You’ve made it through all the

problems in this tutorial. Now, you can put these math

skills to good use the next time you’re out

shopping.

with discounts sales tax and tips learning about percent

Documents

percent slide

review slide

sales price

sales tax example

regular price

lesson slide

discounts sales tax

original price