Shopping & Dining with Proportions

1. Shopping & Dining with Proportions Cornell Notes with Summary Essential Question: How are percents used practically when solving problems dealing with discounts, sales tax, and tips?

2. Discount • An amount by which the cost of an item is reduced. The total price of an item is the cost minus discount. • At a local retail store, you find a pair of jeans that are 30% off. Originally, they cost $59.99. How much money is the sale price of the jeans? • Set up a percent proportion. % = is 30 = x 100 Of 100 $59.99 • Use CMADto find the discount amount (cross multiply and divide) . 30/100 = x/$59.99 cross multiply $59.99 by 30, then divide the product by 100. Your quotient is $18.00 after you round to the nearest cent. • Subtract the discount from the jeans’ original price. $59.99 - $18.00 • Find the final cost of the jeans: $41.99

3. You try it! • Find the total cost of a dinning room set that is $1,200 when it is discounted 25%. • Set up a percent proportion. % = is 25 = x 100 Of 100 $1,200 • Use CMAD to find the discount amount (cross multiply and divide) . 25/100 = x/$1,200 cross multiply $1,200 by 25, then divide the product by 100. Your quotient is $300.00. • Subtract the discount from the dining room set’s original price. $1,200 - $300 • Find the final cost of the jeans: $900

4. Sales Tax • An additional charge added to the cost of an item. The total price of an item is the cost plus tax. • At a local retail store, you purchase a t-shirt for $14.99. How much money will you need to purchase the shirt if sales tax is 7.5%? • Set up a percent proportion. % = is 7.5 = x 100 Of 100 $14.99 • Use CMAD to find the sales tax (cross multiply and divide). 7.5/100 = x/$14.99 cross multiply $14.99 by 7.5, then divide the product by 100. Your quotient is $1.12 after you round to the nearest cent. • Add the tax to the t-shirt’s original price. $14.99 + $1.12 • Final cost of the t-shirt: $16.11

5. You try it! • Find the total cost of a TV that is $298 when sales tax is 6.5%. • Set up a percent proportion. % = is 6.5 = x 100 Of 100 $298 • Use CMAD to find the sales tax (cross multiply and divide) . 6.5/100 = x/$298 cross multiply $298 by 6.5, then divide the product by 100. Your quotient is $19.37. • Add sales tax to the TV’s original price. $298 + $19.37 • Find the final cost of the TV: $317.37

6. Tip or Gratuity • An additional charge added to the cost of a service. The total price is the cost of the service plus tip. • At a local restaurant, you purchase a drink and some dinner. The restaurant bill comes to $17.45 including tax. The waitress did her job well, so you decide to leave a 17% tip. How much money will you spend on dinner? • Set up a percent proportion. % = is 17 = x 100 Of 100 $17.45 • Use CMAD to find the tip amount (cross multiply and divide) 17/100 = x/$17.45 cross multiply $17.45 by 17, then divide the product by 100. Your quotient is $2.97 after you round to the nearest cent. • Add the tip to the restaurant bill. $17.45 + $2.97 • Final cost of dinner: $20.42 *Would you leave a $2.97 tip, or would you round it up to $3.00?

7. You try it! • Find the cost lunch after leaving a 16% tip if the bill comes to $12.57. • Set up a percent proportion. % = is 16 = x 100 Of 100 $12.57 • Use CMAD to find the tip amount (cross multiply and divide) 16/100 = x/$12.57 cross multiply $12.57 by 16, then divide the product by 100. Your quotient is $2.01 after you round to the nearest cent. • Add the tip to the restaurant bill. $12.57 + $2.01 • Final cost of dinner: $14.58 *Would you leave a $2.01 tip, or would you round it to $2.00?

8. Putting it all together • You have $150 to spend shopping at your favorite retail store. They’re having a sale on a huge selection of clothing, and you’re excited to shop. Most items are 30-50% off and you hope you can buy all the items on your list. However, you’re having dinner with your friends afterwards at your favorite restaurant, so you know you’ll spend at least $10.98 before tax and tip on dinner. You must tip the waitress 15-20%, and tax in your area is 6.5%.

9. Putting it all together • Shop wisely, you only have $150, and you must buy dinner. • Using the original prices listed below, pick at least 2 shirts, one pair of pants, and a pair of shoes you can afford– their discounts are also listed. • Remember, tax is 6.5% at both the retail store and the restaurant. • Dinner will cost $10.98 before tax & a 15-20% tip. • $65.00 – Khakis – 50% off $58.00 – Jeans – 40% off • $21.00 – T-Shirt – 35% off $24.99 – Graphic T-Shirt – 30% off • $35.00 – Dress Shirt – 45% off $23.00 – Hawaiian Print Shirt – 50% off • $49.00 – Dress Shoes – 30% off $62.00 – Tennis Shoes – 35% off

10. Summary • Answer the Essential Question in two or more complete sentences. • EQ: How are percents used practically when solving problems dealing with discounts, sales tax, and tips?

11. Homework • Using the order calculated during class today, describe in at least one paragraph the decisions that were made in selecting menu items, as well as tip percentage. Include an explanation of how the totals were calculated.