We often have to add or subtract percentages to find the total cost • Examples of percents that add to the cost – – – – Tip, or gratuity Tax Interest Mark-up • Examples of percents that subtract from the cost – – – – Discount Coupon Sale Mark-down Ex 2) A movie ticket is regularly priced at $9.50 Every Tuesday, the movie theater offers a 20% discount on tickets purchased for the evening movies If you use this discount, what is the sale price of a movie ticket? Sale price = price - discount Find the discount percent 100 = part whole 20 = x 100 9.50 x = $1.90 Subtract the discount from the regular price to find the sale price Sale price = $9.50 - $1.90 Sale price = $7.60 The sale price of a movie ticket is $7.60 Ex 1) A new soccer ball is priced at $37 If the sales tax is 8%, what is the total cost to buy the soccer ball? Total cost = price + tax Find the tax percent 100 = part whole = x 100 37 x = $2.96 Add the price and the tax to find the total cost Total cost = $37 + $2.96 Total cost = $39.96 The soccer ball costs $39.96 including tax Ex 4) A group of friends went to lunch The bill, before sales tax and tip was $37.50 A sales tax of 8% was added The group then tipped 18% on the amount after the sales tax was added a)What was the amount, in dollars of the sales tax? Part = Percent (Whole) The tax for the lunch was $3 Part Part = 0.08 (37.5) Part = b)What was the total amount the group paid, including tax and tip? Total = bill + tax Total = 37.50 + Total = 40.50 Part = Percent (Whole) Total amount = total + tip Total = 40.50 + 7.29 Total = 47.79 The total amount the group paid including tax and tip was $47.79 Ex 4) The Moore family wants to buy a new computer regularly priced at $1,049 Mrs Moore has a coupon for 20% off any item in the store a)How much will the computer cost if they use the coupon? Part = Percent (Whole) Cost = Price – Discount Cost = 1049 – 209.80 Cost = 839.20 The price of the computer with the coupon is $839.20 b)What is the total amount the Moore family paid after the sales tax of 8% was included? Part = Percent (Whole) Total = Cost + Tax Total = 839.20 +6714 Total = 906.34 The price of the computer including tax is $906.34 ... 8% , what is the total cost to buy the soccer ball? Total cost = price + tax Find the tax percent 100 = part whole = x 100 37 x = $2.96 Add the price and the tax to find the total cost Total cost. .. total amount the group paid, including tax and tip? Total = bill + tax Total = 37.50 + Total = 40.50 Part = Percent (Whole) Total amount = total + tip Total = 40.50 + 7.29 Total = 47.79 The total. .. (Whole) Cost = Price – Discount Cost = 1049 – 209 .80 Cost = 83 9.20 The price of the computer with the coupon is $83 9.20 b)What is the total amount the Moore family paid after the sales tax of 8% was