3 Our Learning GoalStudents will be able to determine and construct fractions, decimals, and percents by understanding their relationships, solving for the unknown, solving increase and decrease, solving sales tax/total cost contextual problems and compute simple interest.
4 Our Learning Goal Assignments Learn to relate decimals, fractions, & percents (8-1)Learn to find percents (8-2)Learn to find a number when the percent is known (8-3)Learn to find percent increase and decrease (8-4)Learn to estimate with percents (8-5)Learn to find commission, sales tax, and withholding tax (8-6)Learn to compute simple interest (8-7)
5 Learning Goal Scale Students are able to determine & construct fractions, decimals, & percents: 4321Clear understanding their relationshipsAble to solve for the unknownUnderstands how to solve for increase & decreaseCalculating solving sales tax/total cost contextual problemsComputing simple interestUnderstands their relationshipsSome solving for the unknownDifficulty solving for increase & decreaseDifficulty solving for the unknownSome understanding their relationshipsEven with help, no understanding or skill demonstrated
12 Real estate agents often work for commission Real estate agents often work for commission. A commission is a fee paid to a person who makes a sale. It is usually a percent of the selling price. This percent is called the commission rate.Often agents are paid a commission plus a regular salary. The total pay is a percent of the sales they make plus a salary.commission rate sales = commission
13 Additional Example 1: Multiplying by Percents to Find Commission Amounts A real-estate agent is paid a monthly salary of $900 plus commission. Last month he sold one condominium for $65,000, earning a 4% commission on the sale. How much was his commission? What was his total pay last month?First find his commission.4% $65,000 = c commission rate sales = commission
14 Additional Example 1 Continued 0.04 65,000 = c Change the percent to a decimal.2600 = c Solve for c.He earned a commission of $2600 on the sale.Now find his total pay for last month.$ $900 = $ commission + salary = total payHis total pay for last month was $3500.
15 Try This: Example 1A car sales agent is paid a monthly salary of $700 plus commission. Last month she sold one sports car for $50,000, earning a 5% commission on the sale. How much was her commission? What was her total pay last month?First find her commission.5% $50,000 = c commission rate sales = commission
16 Try This: Example 1 Continued 0.05 50,000 = c Change the percent to a decimal.2500 = c Solve for c.The agent earned a commission of $2500 on the sale.Now find her total pay for last month.$ $700 = $ commission + salary = total payHer total pay for last month was $3200.
17 Sales tax is the tax on the sale of an item or service Sales tax is the tax on the sale of an item or service. It is a percent of the purchase price and is collected by the seller.
18 Additional Example 2: Multiplying by Percents to Find Sales Tax Amounts If the sales tax rate is 6.75%, how much tax would Adrian pay if he bought two CDs at $16.99 each and one DVD for $36.29?CD: 2 at $ $33.98DVD: 1 at $ $36.29$70.27 Total Price = Convert tax rate to a decimal and multiply by the total price.Adrian would pay $4.74 in sales tax.
19 Try This: Example 2Amy rents a hotel for $45 per night. She rents for two nights and pays a sales tax of 13%. How much tax did she pay?$45 2 = $90 Find the total price for the hotel stay.$90 0.13 = $ Convert tax rate to a decimal and multiply by the total price.Amy spent $11.70 on sales tax.
20 A tax deducted from a person’s earnings as an advance payment of income tax is called withholding tax.
21 Additional Example 3: Using Proportions to Find the Percent of Tax Withheld Anna earns $1500 monthly. Of that, $ is withheld for Social Security and Medicare. What percent of Anna’s earnings are withheld for Social Security and Medicare?Think: What percent of $1500 is $114.75?Solve by proportion:114.751500n100=n 1500 = 100 Find the cross products.
22 Additional Example 3 Continued 1500n = 11,475 Divide both sides by 1500.11,4751500n=n = 7.657.65% of Anna’s earnings is withheld for Social Security and Medicare.
23 Try This: Example 3BJ earns $2500 monthly. Of that, $500 is withheld for income tax. What percent of BJ’s earnings are withheld for income tax?Think: What percent of $2500 is $500?Solve by proportion:5002500n100=n 2500 = 100 500 Find the cross products.
24 Try This: Example 3 Continued 2500n = 50,000 Divide both sides by 2500.500002500n=n = 2020% of BJ’s earnings are withheld for income tax.
25 Additional Example 4: Dividing by Percents to Find Total Sales A furniture sales associate earned $960 in commission in May. If his commission is 12% of sales, how much were his sales in May?Think: $960 is 12% of what number?Solve by equation:960 = 0.12 s Let s = total sales.9600.12= s Divide each side by 0.12.The associate’s sales in May were $8000.
26 Try This: Example 4A sales associate earned $770 in commission in May. If his commission is 7% of sales, how much were his sales in May?Think: $770 is 7% of what number?Solve by equation:770 = 0.07 s Let s represent total sales.7700.07= s Divide each side by 0.07.The associate’s sales in May were $11,000.
27 Lesson Quiz: Part 11. The lunch bill was $8, and you want to leave a 15% tip. How much should you tip?2. The sales tax is 5.75%, and the shirt costs $20. What is the total cost of the shirt?3. As of 2001, the minimum hourly wage was $5.15. Congress proposed to increase it to $6.15 per hour. To the nearest percent, what is the proposed percent increase in the minimum wage?$1.20$21.1519%
28 Lesson Quiz: Part 24. It costs a business $13.30 to make its product. To satisfy investors, the company needs to make $4 profit per unit. To the nearest percent, what should be the company’s markup?30%