1. Problem Solving with Proportional Relationships
Lesson 12: Percents

2. Vocabulary

3. Vocabulary
Discount: a percent subtracted from the cost of an item to reduce the final price. 
Sale Price: the price of an item after the discount is subtracted.
Markdown: a percent subtracted from the cost of an item to determine the sale price. 

4. Video

5. Percent Proportion

6. Discount Bar Model
In the bar model, the original price is equal to the sale price plus the discount.  To find the sale price, subtract the discount from the original price. 

7. Discount Example

8. Discount Equation 100% - % Discount Change % to decimal
Multiply by the original price to find the sale (discounted) price. 
EX: 15% off of $29.89
100-15=85%
0.85
0.85 x 29.89= $25.41 Sale Price
Sale Price= Original price - (% of discount x original price)

9. Discount Proportion
% Discount = Amount of Discount
        100                  Original Price 

10. Tax/Tip/Commission/Markup Bar Model
In the bar model, the total price is equal to the original price plus the tax/tip/commission/markup.  To find the original price, subtract the markup from the total price.  

11. Tax/Tip/Commission/Markup Examples

12. Tax/Tip/Commission/Markup Equation
Change % to decimal 
Multiply by the original price to find the total price (including tax/tip/commission/interest/markup.  
EX: 18% tip for $34.99 dinner bill
=118%
1.18
1.18 x 34.99= $41.29 Total with Tip
Total Price= Original price + (% of markup x original price)

13. Markup Proportion
% Markup = Amount of Markup 
        100              Original Price 

14. Simple Interest Bar Model
In the bar model, the total amount to pay back is equal to the amount borrowed plus the interest.  To find the amount borrowed, subtract the interest from the total amount to pay back.   

15. Simple Interest Example

16. Simple Interest Equation

17. Practice
Textbook pg
Workbook pg