1. Warm Ups 1)Thirty is 12% of what number? 2)Find 115% of 140. 3)Find I, if p = $950, r = 9%, and t = 6 months Answers: 1)250 2)161 3)$42.75

2. Return Ch. 3 test – questions?

3. 4 - 5 Percent of Change Objective: To solve percent word problems. Standard 5.0

4. Example 1 Find the final price of a pair of $106 jeans if they are discounted 12% (sales tax not included).

5. Example 2 40% off Originally $34 How much is the sale price? ( percent decrease) What will the price be after 7% tax? (percent increase)

6. Soooo… Discount is subtracted Tax is added Always subtract discount then add tax!

7. Coat: $195.00 Discount: 40% Sales tax: 5% How much is the sale price? (percent decrease) What will the price be after 5% tax? (percent increase) Example 3

8. Try with a mathlete Find the final price of a $55 shirt if it is discounted 15% and the sales tax is 8%. Answer: $50.49

9. ZONK 1. What percent of 16 is 5.12? 32% 2. What number is 25% of 64? 16 3. -6 = x + 4 8 -80

10. ZONK 4. Original: 78 pennies new: 36 pennies decrease, 54% 5. Original: $62 new: $98 increase 58% 6. Television: $299 Tax: 4.5% $312.46 7. Jacket: $64 discount: 30% tax: 4% $46.59

11. Homework Percent Word Problems *Read the problem carefully to determine which equation to use! 4 types:Words to look for:Things to know: is % of“is” and “of”“is” means equal “of” means times “what” means variable % written as decimal I = prt“interest”I = interest earned ($) P = Principle ($) R = interest rate (% to decimal) T = time (in years) % increase“increase” or “sales tax” New – old = % old 100 % decrease“decrease” or “sale” Old – new = % old 100

12. Homework Pg. 225 #21 – 29 all

13. Math Lab Warm Ups 1)Twenty is 18% of what number? 2)Find 135% of 120. 3)Find I, if p = $1200, r = 7%, and t = 9 months

14. Example 2 40% off Originally $34 How much is the sale price? ( percent decrease) What will the price be after 7% tax? (percent increase)