Calculate Tax, Tip, and Discount

7.RP.3 Reteach - Percents, Tax, Tip, Discount

Percent

A percent literally means "per 100" or "out of 100".

Given a ratio, we can convert it into a percentage be converting the denominator to 100.

How does a proportion change to a percent?

• find out how much to multiply the denominator by to reach 100.

• In this example the original denominator is 10, so we just need to multiply by 10 to get to 100.

How does a proportion change to a percent?

• Then we multiply the numerator by the same amount to get the final percentage!

• In this case the percentage is 60.

Multiple Choice

45/50 is what percent?

• 45%

• 95%

• 9%

• 90%

Multiple Choice

2/5 is what percent?

• 40%

• 25%

• 52%

• 2.5%

Percent Equation Set-up

• We use this equation to find out what percentage a ratio is.

• We use percents to find out the proportional amount of something.

Percent Equation Set-up

• To be able to use this equation we need to have 2 of the unknown pieces:

• The Whole: what is the total we are looking at?

• The Part: what portion of the whole are we dealing with?

• The Percent: what is the equivalent ratio over 100?

Percent Equation Example:

• The Part: In this case the number of strikes

• The Whole: the number of frames bowled

• The Percent: this is what we must figure out.

Percent Equation Example:

• You can use the same model we used before. This means we would multiply the numerator and denominator by 10/3 to get our solution.

• The answer is 40 percent

Percent Equation Example:

• Or we could rewrite the equation as shown here:

Multiple Choice

What is 30% of 50?

• 16

• 16.3

• 17.4

• 15

Multiple Choice

Bob wants to buy a computer. He needs to raise 10% to be able to put it on layaway. If the computer costs $700, how much will he need to save?

• $140

• $100

• $70

• $700

Multiple Choice

Josie makes 20% commission on every car that she sells. If she sells a car for $50,000, how much commission did she make?

• $40,000

• $10,000

• $1,000

• $4,000

Multiple Choice

Harris ran a total of 15 miles last week. She ran 4.2 of those miles on Monday. What percent of her total distance did she run on Monday?

• 28%

• 42%

• 72%

• 58%

Sales Tax

• Sales tax is a percentage of the cost of things you are buying.

• It is then added to the end of your bill.

Sales Tax

• In this example the sales tax percent is 7%

• The purchase amount is $9.99

• The total sales tax you will pay will be $0.70

Sales Tax

• The total cost you will pay then becomes the purchase amount plus the sales tax

• The purchase amount is $9.99

• The total sales tax you pay is $0.70

• The total cost is $10.69

Multiple Choice

Carrie's car is valued at $11,250. If the property tax rate is 1.5%, how much tax does she owe?

• $1687.50

• $168.75

• $16.88

• $1.69

Multiple Choice

You bought several Christmas presents that cost $58.50. The sales tax was 6.5%. How much money did you spend in taxes?

• 3.80

• 8.30

• 62.30

• 54.70

Multiple Choice

You bought several Christmas presents that cost $58.50. The sales tax was 6.5%. How much money did you spend on your family's Christmas presents?

• 3.80

• 8.30

• 62.30

• 54.70

Multiple Choice

At McDonald’s a McChicken cost $1.49. Meals tax is 5%. What is the total cost?

• $1.54

• $1.65

• $1.56

• $1.42

Multiple Choice

A water bottle costs $9.45. Sales tax is 7%. What is the total cost?

• $9.52

• $0.66

• $10.11

• $8.79

Tip

(Also Called Gratuity)

• Tip is calculated based off of the purchase amount BEFORE you add the tax.

• The Tip amount is also calculated using a percent. (Like Tax)

• A Tip is then added on at the end.

Tip

(Also Called Gratuity)

• In this case the purchase amount is $24.99

• The percent you wish to tip is 18%

• The tip amount you will pay is $4.50

Multiple Choice

Johan's bill for food was $32.64. He left a tip of 16%. How much did he leave for a tip?

• $7.73

• $16.00

• $5.22

• $37.86

Multiple Choice

You get a new haircut that costs $15. You give a tip of 20%. What is the total cost?

• $35.00

• $3.00

• $18.00

• $12.00

Multiple Choice

Breakfast at Denny’s cost $8.63. You give a 15% tip. What is the total cost?

• $8.78

• $1.29

• $9.92

• $7.34

Multiple Choice

Dinner at the Olive Garden cost $52.37. You leave a 20% tip. What is the total cost?

• $72.37

• $10.47

• $62.84

• $41.90

Finding Tax and Tip for the same purchase

• Here our purchase amount is $43.28

• We must find our tax

• We must find out Tip

• Then we take the total to find out how much we spend

Multiple Choice

You go to a restaurant and your total cost (before tax and tip) is $34.00. How much will the 6% sales tax cost you?

• $20.40

• $2.04

• $0.24

• $2.40

Multiple Choice

You go to a restaurant and your total cost (before tax and tip) is $34.00. How much will a 20% tip cost you?

• $6.96

• $0.68

• $68.00

• $6.80

Multiple Choice

You go to a restaurant and your total cost (before tax and tip) is $34.00. How much will your total bill be if the tax is 6% and you decide to leave a 20%?

• $52.96

• $36.68

• $68.04

• $42.80

Multiple Choice

You restaurant bill is $50.00. How much is your total cost after a 6% tax and a 20% tip? (Tip is calculated BEFORE tax)

• $63.00

• $53.00

• $50.00

• $1000

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