2. 1. a. What is 20% of 80? 4 b. Why is four wrong? %
3. 1. a. What is 20% of 80? 1600 c. Why is one thousand six hundred wrong? %
4. 1. a. Find 20% of 80. 16 or 16.00 d. Why is one fourth right? 80 x .20 00 160 16 00 %
5. 2. a. What is 35% of 20? 7.35 b. Why is seven and thirty-five hundredths wrong? %
6. 2. a. What is 35% of 20? 700 c. Why is seven hundred wrong? %
7. 2. a. Find 35% of 20. 7 or 7.00 d. Why is seven right? 20 x .35 100 60 7.00
8. 3. a. There is a discount of 25% off on a $60 pair of shoes. How much are the shoes? $25 b. Why is twenty-five dollars wrong? %
9. 3. a. There is a discount of 25% off on a $60 pair of shoes. How much are the shoes? $15 c. Why is fifteen dollars wrong? %
10. 3. a. There is a discount of 25% off on a $60 pair of shoes. How much are the shoes? $45 d. Why is forty-five dollars correct? $60 x .25 300 120 $15.00 $60 - 15 $45
11. 4. a. A shirt cost $30 plus 7% tax. What is the total cost? $37 b. Why is thirty-seven dollars wrong? %
12. 4. a. A shirt cost $30 plus 7% tax. What is the total cost? $2.10 c. Why is two dollars and ten cents incorrect? %
13. 4. a. A shirt cost $30 plus 7% tax. What is the total cost? $32.10 d. Why is thirty-two dollars and ten cents correct? $30 x .07 $2.10 $30.00 + 2.10 $32.10
14. 5. a. A $300 bike is on sale. How much is the cost? $275 b. Why is two hundred seventy-five dollars wrong? %
15. 5. a. A $300 bike is on sale. How much is the cost? $75 c. Why is seventy-five dollars wrong? %
16. 5. a. A $300 bike is on sale. How much is the cost? $225 d. Why is two hundred twenty-five dollars correct? $300 x .25 1500 60 $75.00 $300 - 75 $225
17. A shirt that costs $30 last month, now costs $45. What is the percent of change? 15 c. Why is 15 incorrect? %
18. A shirt that costs $30 last month, now costs $45. What is the percent of change? 50% Why is 1/2 correct? $45 - $30 $15 $15 ÷ $30 .5 = 1/2
Send comments and feedback to Don Fisher: fisher_d@madera.k12.ca.us Have the students write down their answers for each question as it is revealed. Make sure there is sufficient “wait time” for them to write. You may have them work with partners and discuss before clicking next. Be sure to preview the whole presentation and estimate the time for your class to work. You may wish to break the presentation into smaller parts.