Mathematics
Grade 9
15 min
Find the percent tax discount and more
Find the percent tax discount and more
Tutorial Preview
1
Introduction & Learning Objectives
Learning Objectives
Calculate the final price of an item after a percentage discount.
Calculate the total cost of an item including sales tax.
Solve multi-step problems involving both a discount and a tax.
Determine the original price of an item given the sale price and percent discount.
Calculate the percent discount given the original and sale prices.
Calculate a tip (gratuity) and the total bill for a service.
Compare different discount offers to determine the better value.
Ever seen a '30% OFF' sign and wondered what you'd actually pay at the register? 🛍️ Let's master the math so you always know!
This tutorial will teach you how to handle real-world percent calculations like discounts, sales tax, and tips. Understanding these concepts is a crucial...
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Key Concepts & Vocabulary
TermDefinitionExample
Original Price (List Price)The initial price of an item before any discounts are applied or taxes are added.A new pair of sneakers has a price tag of $120. This is the original price.
DiscountA reduction in the original price of an item, usually expressed as a percentage.A 25% discount on a $120 pair of sneakers means the price is reduced by $30.
Sale PriceThe price of an item after a discount has been applied, but before tax.After a 25% ($30) discount, the $120 sneakers have a sale price of $90.
Sales TaxA percentage of the sale price added to the cost of an item, which is collected by the government.If the sales tax is 8% on the $90 sale price, an additional $7.20 is added to the cost.
Tip (Gratuity)An extra amount of money given to a service worker, usually calcul...
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Core Formulas
Sale Price Formula
Sale Price = P \cdot (1 - r)
Use this for a one-step calculation to find the price after a discount. 'P' is the Original Price and 'r' is the percent discount as a decimal.
Total Cost with Tax Formula
Total Cost = S \cdot (1 + t)
Use this for a one-step calculation to find the final cost including tax. 'S' is the Sale Price and 't' is the percent tax as a decimal.
Finding the Original Price Formula
P = \frac{\text{Sale Price}}{1 - r}
Use this algebraic rearrangement to find the original price ('P') when you know the sale price and the discount rate ('r').
4 more steps in this tutorial
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Challenging
An item has an original price of P dollars. It is on sale with a discount rate of r (as a decimal), and the sales tax rate is t (as a decimal). Which expression represents the final total cost of the item?
A.P(1 - r + t)
B.P(1 - r)(1 + t)
C.P(1 - r - t)
D.P(1 + t) - P(r)
Challenging
At what original price is a 20% discount financially equivalent to a $50 mail-in rebate?
A.$100
B.$200
C.$250
D.$500
Challenging
A clearance item is marked down by 30%. At the register, an additional 20% is taken off the already discounted price. What is the total equivalent single discount percentage from the original price?
A.50%
B.44%
C.56%
D.40%
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