Mathematics
Grade 10
15 min
Percent of a number: tax, discount, and more
Percent of a number: tax, discount, and more
What you'll learn
- Calculate the amount of sales tax on an item and the final price after tax, with 80% accuracy, using decimal and percentage conversions.
- Determine the sale price of an item after a given discount percentage is applied, showing the steps of calculation, in at least 3 out of 4 practice problems.
- Explain, in writing, the difference between calculating a discount and calculating sales tax, providing a real-world example for each in a short paragraph.
- Solve multi-step word problems involving percent of a number, including scenarios like calculating tips or markups, with at least 70% accuracy.
- Identify and define the terms 'tax', 'discount', 'tip', and 'markup' in the context of percentage calculations, scoring at least 4 out of 5 on a matching quiz.
Tutorial Preview
1
Introduction & Learning Objectives
Learning Objectives
Calculate the final price of an item after applying a single percentage discount or tax.
Solve multi-step problems involving sequential percentages, such as a discount followed by a tax.
Determine the original price of an item given the final price and the percentage change (reverse percentages).
Calculate percent increase and decrease in various contexts, including profit, loss, and commission.
Apply percentage calculations to solve real-world financial literacy problems, including simple interest and gratuity (tips).
Formulate and solve algebraic equations to represent percentage problems.
Analyze and compare different percentage-based scenarios to make informed financial decisions.
Ever seen a '50% off, then an extra 20% off' sale and wonde...
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Key Concepts & Vocabulary
TermDefinitionExample
PercentA ratio expressed as a fraction of 100. The word 'percent' literally means 'per hundred'.50% is equivalent to the fraction 50/100 or the decimal 0.5.
Sales TaxA percentage of the selling price of a good or service that is added to the cost.A 7% sales tax on a $20 item adds $1.40 ($20 * 0.07) to the price, making the total $21.40.
DiscountA reduction in the usual price of an item, typically expressed as a percentage.A 25% discount on an $80 jacket saves you $20 ($80 * 0.25), making the sale price $60.
CommissionA fee paid to an agent or employee for transacting a piece of business or performing a service, often calculated as a percentage of the sale amount.A real estate agent earning a 3% commission on a $300,000 house sale makes $9,000.
Gra...
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Core Formulas
Calculating a Percentage of a Number
\text{Part} = \frac{\text{Percent}}{100} \times \text{Whole}
Use this fundamental formula to find a specific percentage of a given total amount. 'Percent' is the number (e.g., 25 for 25%), and 'Whole' is the original number.
Final Price with Tax/Discount
\text{Final Price} = \text{Original Price} \times (1 \pm \frac{\text{Percent}}{100})
A shortcut to find the final price. Use '+' for a percentage increase (like tax or tip) and '-' for a percentage decrease (like a discount). For example, a 15% discount is calculated by multiplying by (1 - 0.15) = 0.85.
Reverse Percentage Calculation
\text{Original Price} = \frac{\text{Final Price}}{(1 \pm \frac{\text{Percent}}{100})}
Use this to find the or...
5 more steps in this tutorial
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Challenging
Store A offers a 30% discount on a $500 camera. Store B offers the same camera with a 20% discount, followed by an additional 15% discount on the sale price. Which store offers a better final price, and by how much?
A.Store A, by $10
B.Store B, by $10
C.Store A, by $20
D.Their prices are the same.
Challenging
A coat is sold for $240, which represents a 25% profit on the cost price for the store. If the store owner wanted to make a 40% profit instead, what should the selling price have been?
A.$256
B.$268.80
C.$336
D.$250
Challenging
The price of a stock was increased by p%. Later, the new price was decreased by p%. If the final price was 96% of the original price, what is the value of p?
A.4
B.16
C.20
D.2
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Frequently asked questions
What grade level is "Percent of a number: tax, discount, and more"?
Percent of a number: tax, discount, and more is a Grade 10 Mathematics lesson on ExcelOS.
What will I learn in Percent of a number: tax, discount, and more?
You'll be able to: Calculate the amount of sales tax on an item and the final price after tax, with 80% accuracy, using decimal and percentage conversions; Determine the sale price of an item after a given discount percentage is applied, showing….
Is "Percent of a number: tax, discount, and more" free to practice?
Yes. You can read the tutorial preview for free, and signing up for a free ExcelOS account unlocks the full tutorial and all practice questions with instant feedback.
How many practice questions are included with Percent of a number: tax, discount, and more?
This lesson includes 25 practice questions across multiple difficulty levels, each with instant feedback and explanations.