# Solving problems involving discounts at sales and sales tax.

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Solving problems involving discounts at sales and sales tax.
Number Sense 1.4 Calculate given percentages of quantities and solve problems involving discounts at sales, interest earned, and tips. Objective: Students will find the discount and sale price of an item and find the tax and total price of an item after taxes.

California Blue Prints
Number Sense 25 39% Standard Set 1.0* Students compare and order positive and negative fractions, decimals, and mixed numbers. Students solve problems involving fractions, ratios, proportions, and percentages: 1.1* Compare and order positive and negative fractions, decimals, and mixed numbers and place them on a number line. 3 1.2* Interpret and use ratios in different contexts (e.g., batting averages, miles per hour) to show the relative sizes of two quantities, using appropriate notations (a/b, a to b, a:b). 1 1.3* Use proportions to solve problems (e.g., determine the value of N if 4/7 = N/21, find the length of a side of a polygon similar to a known polygon). Use cross- multiplication as a method for solving such problems, understanding it as the multiplication of both sides of an equation by a multiplicative inverse. 6 1.4* Calculate given percentages of quantities and solve problems involving discounts at sales, interest earned, and tips. 5

How to find the sales tax!
First find out what tax rate you will be paying. In California the tax rate is 8.25%! Convert your percentage to a decimal by moving your decimal two spaces to the left. Ex % = (Don’t forget to add a zero) Multiply the decimal form of the tax rate by the price of the item you are purchasing. Ex x \$ cost of the item

How to find the sales tax!
So if an item costs \$5.00 Sales tax is 8.25% Convert 8.25% to .0825 So x \$5 = \$.41 The sales tax is \$.41 But the total price of the item is \$ \$.41 = \$5.41

How to find the Discount & Discounted Price
Find out the % of the discount. Convert the % to a decimal. Multiply the decimal by the original price. Take the answer in step 2 and subtract it from the original price. Example Discount 20% = .20, \$10 x .20 = \$2.00 \$ \$2.00 = \$8.00

\$50.00 149.99 \$162.36 \$9.20 \$239.19 \$.74 \$165.35 \$189.99 \$71.20 \$17.80 \$53.04 \$4.04 \$48.71 \$3.71 \$10.83 \$.83

The object of the game: Solve the math problem.
Cross out the answer on the bingo card. The first three students with four in a row win!

Hollister Shirt \$10 The tax is 8.25%
1. How much would you spend on taxes for this shirt? \$.83 2. What would be the total cost of this shirt? \$10.83

\$45.00 iPod shuffle 1GB tax rate = 8.25%
3. What will the sales tax be if you purchase this item? \$3.71 4. What will the total price be if you purchase this item? \$48.71

E-matic 4GB Video MP3 Player with 2
E-matic 4GB Video MP3 Player with 2.4" Screen, Camera and Video Recorder \$49.00 Tax rate 8.25% 5. What will be the total of the state sales tax? \$4.04 6. What will be the total price of the MP3 Player after the state tax of 8.25% is applied? \$53.04

If this Tony Romo Jersey was 20% off, 7. What would the discount be. 8
If this Tony Romo Jersey was 20% off, 7. What would the discount be? 8. What would be the sale price? Tony Romo Jersey \$89

Xbox 360 for \$199.99 The Discount is 25% 9. What is the discount?
\$ 50.00 10. What is the price after the discount? \$149.99 11. What is the price after the discount and after taxes? \$162.36

Ipod Touch for \$229.99 The tax rate is 4% 12. What is the tax? \$ 9.20
13. What is the total price after taxes? \$239.19