1. Applications with Percents

2. Objective: 7.1.01 Develop and use ratios, proportions, and percent to solve problems Essential Question: How can I apply my understanding of percents to make more informed shopping decisions? What is the best “DEAL” or Value?

3. Vocabulary: Sales Tax: an additional amount of money charged on the items people buy; the government uses this money to operate the country. (Not all countries, states or cities have a tax)! Some items are taxed at different rates. Discount: the amount of money (or percent) by which the regular price of an item is reduced. Tip: also known as gratuity, is money given to a person who provides a service, and is added to the cost of that service. (In some places it is automatically added!) Applications with Percents

4. Real World Choices: Sam has a dilemma. He wants to purchase a game but cannot decide where to buy it. Target is selling them for $399.99 with a 15% discount. Best Buy is selling them for $375.99 but only a 10% discount. Where should Sam buy his game? Applications with Percents

5. But What About If… If… Applications with Percents

6. Real World Example: Target was selling them for $399.99 with a 20% discount. Best Buy was selling them for $375.99 and a 15% discount. Applications with Percents

7. COMPARE PURCHASE DECISIONS Store-1Store-2 Original Cost$399.99$375.99 Discount Rate15%10% Amount of Discount Hint: Round.15 x 399.99.15 x 400 =.1 x 375.99.1 x 376 = $ Discount$60$ 37.60 New Price = Original - Discount 400 – 60 = $360 376 – 37.60 = $338.4

8. Applications with Percents Example 1: Finding Total Cost A calculator costs $90 and the sales tax is 6%. What is the total cost? $95.40 Total Cost = Original Cost + Sales Tax First calculate the Sales Tax 6% OF $90 $5.40 Total Cost $90.00 + $5.40 Total Cost $95.40

9. Applications with Percents Example 2: Finding Total Cost A laptop costs $475 and the sales tax is 7½%. What is the total cost? $510.63 Total Cost = Original Cost + Sales Tax First calculate the Sales Tax 7½% OF $475 $35.63 Total Cost $475.00 + $35.63 Total Cost $510.63

10. Another way to think about: TOTAL COST Total Cost = $Original + $TAX 6% Tax on an Original price of $90..06 x 90 = $5.40 tax SO: 90 + 5.40 = $95.40 OR: Total Cost = 90 (1.06) Total Cost = ORIGINAL x (1 + Rate) $95.40

11. Applications with Percents Example 3: Finding Sale Price A snowboard has a regular price of $169 but is on sale for 35% off. What is the sale price? $109.85 Sale Price = Original Cost – Discount First calculate the discount 0.35 x 169 $59.15 Total Cost $169.00 – $59.15 Total Cost $109.85

12. Applications with Percents Example 4: Finding Sale Price A new coat has a regular price of $185 but is on sale for 33% off. What is the sale price? $123.95 Sale Price = Original Cost – Discount First calculate the Discount 33% OF $185 $61.05 Total Cost $185.00 – $61.05 Total Cost $123.95

13. Another way to think about Sale Price Sales Price = Original - Discount 20% Discount off an Original price of $180..2 x 180 = $36 SO: 180 – 36 = $144 IF the DISCOUNT was 20%, (Percent means 100) SO, that means the Sales Price is 80% of the Original!.8 x 180 = $144.00

14. Applications with Percents Example 5: Finding Total Cost A meal at Pizza Inn cost $25.85. The tax is 8% and Mr. Williams wanted to leave a 15% tip. What was the TOTAL AMOUNT of the meal? $31.80 Total Cost = Cost of Meal + Tax + Tip First calculate the tax 8% OF $25.85 0.08 x 25.85 $2.07 Next calculate the tip 15% OF $25.85 0.15 x 25.85 $3.88 25.85 $2.07 $3.88

15. Applications with Percents Example 6: Finding Percent of Discount An electric guitar was originally $299.95 but on sale for $179.99. What is the percent of discount? 40% Discount = Original Cost – Sale Price = $299.95 – 179.99 = $119.96 Use the Percent Proportion To Calculate Percent of Discount IS OF % 100

16. Applications with Percents Example 7: Finding Percent of Markup In the last 6 months the average price for a gallon of unleaded gasoline has risen from $2.85 to $3.10. What is the percent of markup? 8.7% Markup = New Price – Old Price = $3.10 – $2.85 = $0.25 Use the Percent Proportion To Calculate Percent of Discount IS OF % 100

17. When Calculating Percents of Markup and Discount: Applications with Percents Always Remember… You can use the percent proportion or the percent of change formula to make your calculations. If you choose to use the percent proportion you have to calculate the change first and use that as your IS and use the original price as your OF.

18. PRACTICE with TAX and DISCOUNT ItemOriginal Cost Tax or Discount Rate Amount of Tax or Discount Total Cost CD Player$99.005% tax Computer$1,500.0025% Discount Skateboard119.5020% Off Notebook$4.308% Tax Book$24.954.5% Tax Sweater$39.6040% Discount

19. Independent Practice: Determine the final cost for each example: 1. $99 CD Player, 5% Tax 2. $1,500 Computer, 25% Discount 3. $119.50 Skateboard, 20% Off 4. $4.30 Notebook, 8% Tax 5. $24.95 Book, 4.5% Tax 6. $39.60 Sweater, 40% Discount Applications with Percents = $103.95 = $1125.00 = $$95.60 = $4.64 = $26.07 = $23.76

20. Summary: Applications with Percents Always Remember…

21. Applications with Percents HOMEWORK