![Page 1: Bellwork 1. Find 30% of 40. 2. Find 28% of 60. Solve for x. 3. 22 = x(50) 4. 17.2 = x(86) 5. 20 is what percent of 80? 6. 36 is what percent of 30? 16.8](https://reader036.vdocuments.us/reader036/viewer/2022062410/5697bfbc1a28abf838ca144e/html5/thumbnails/1.jpg)
Bellwork
1. Find 30% of 40.
2. Find 28% of 60. Solve for x.
3. 22 = x(50)
4. 17.2 = x(86)
5. 20 is what percent of 80?
6. 36 is what percent of 30?
16.8
12
0.2
0.44
25%
120%
![Page 2: Bellwork 1. Find 30% of 40. 2. Find 28% of 60. Solve for x. 3. 22 = x(50) 4. 17.2 = x(86) 5. 20 is what percent of 80? 6. 36 is what percent of 30? 16.8](https://reader036.vdocuments.us/reader036/viewer/2022062410/5697bfbc1a28abf838ca144e/html5/thumbnails/2.jpg)
Percent Increase and Percent Decrease
![Page 3: Bellwork 1. Find 30% of 40. 2. Find 28% of 60. Solve for x. 3. 22 = x(50) 4. 17.2 = x(86) 5. 20 is what percent of 80? 6. 36 is what percent of 30? 16.8](https://reader036.vdocuments.us/reader036/viewer/2022062410/5697bfbc1a28abf838ca144e/html5/thumbnails/3.jpg)
Find percent increase and decrease.
Objective
![Page 4: Bellwork 1. Find 30% of 40. 2. Find 28% of 60. Solve for x. 3. 22 = x(50) 4. 17.2 = x(86) 5. 20 is what percent of 80? 6. 36 is what percent of 30? 16.8](https://reader036.vdocuments.us/reader036/viewer/2022062410/5697bfbc1a28abf838ca144e/html5/thumbnails/4.jpg)
• A percent change is an increase or decrease given as a percent of the original amount. Percent increase describes an amount that has grown and percent decrease describes an amount that has be reduced.
![Page 5: Bellwork 1. Find 30% of 40. 2. Find 28% of 60. Solve for x. 3. 22 = x(50) 4. 17.2 = x(86) 5. 20 is what percent of 80? 6. 36 is what percent of 30? 16.8](https://reader036.vdocuments.us/reader036/viewer/2022062410/5697bfbc1a28abf838ca144e/html5/thumbnails/5.jpg)
Find each percent change. Tell whether it is a percent increase or decrease.
From 8 to 10
= 0.25
= 25% Write the answer as a percent.
Simplify the numerator.Simplify the fraction.
8 to 10 is an increase, so a change from 8 to 10 is a 25% increase.
![Page 6: Bellwork 1. Find 30% of 40. 2. Find 28% of 60. Solve for x. 3. 22 = x(50) 4. 17.2 = x(86) 5. 20 is what percent of 80? 6. 36 is what percent of 30? 16.8](https://reader036.vdocuments.us/reader036/viewer/2022062410/5697bfbc1a28abf838ca144e/html5/thumbnails/6.jpg)
Helpful Hint
Before solving, decide what is a reasonable answer. For Example 1A, 8 to 16 would be a 100% increase. So 8 to 10 should be much less than 100%.
![Page 7: Bellwork 1. Find 30% of 40. 2. Find 28% of 60. Solve for x. 3. 22 = x(50) 4. 17.2 = x(86) 5. 20 is what percent of 80? 6. 36 is what percent of 30? 16.8](https://reader036.vdocuments.us/reader036/viewer/2022062410/5697bfbc1a28abf838ca144e/html5/thumbnails/7.jpg)
From 75 to 30
= 0.6
= 60% Write the answer as a percent.
Simplify the numerator.Simplify the fraction.
75 to 30 is a decrease, so a change from 75 to 30 is a 60% decrease.
Find the percent change. Tell whether it is a percent increase or decrease.
![Page 8: Bellwork 1. Find 30% of 40. 2. Find 28% of 60. Solve for x. 3. 22 = x(50) 4. 17.2 = x(86) 5. 20 is what percent of 80? 6. 36 is what percent of 30? 16.8](https://reader036.vdocuments.us/reader036/viewer/2022062410/5697bfbc1a28abf838ca144e/html5/thumbnails/8.jpg)
From 200 to 110
= 0.45
= 45% Write the answer as a percent.
Simplify the numerator.Simplify the fraction.
200 to 110 is a decrease, so a change from 200 to 110 is a 45% decrease.
Find each percent change. Tell whether it is a percent increase or decrease.
![Page 9: Bellwork 1. Find 30% of 40. 2. Find 28% of 60. Solve for x. 3. 22 = x(50) 4. 17.2 = x(86) 5. 20 is what percent of 80? 6. 36 is what percent of 30? 16.8](https://reader036.vdocuments.us/reader036/viewer/2022062410/5697bfbc1a28abf838ca144e/html5/thumbnails/9.jpg)
From 25 to 30
= 0.20
= 20% Write the answer as a percent.
Simplify the numerator.Simplify the fraction.
25 to 30 is an increase, so a change from 25 to 30 is a 20% increase.
Find each percent change. Tell whether it is a percent increase or decrease.
![Page 10: Bellwork 1. Find 30% of 40. 2. Find 28% of 60. Solve for x. 3. 22 = x(50) 4. 17.2 = x(86) 5. 20 is what percent of 80? 6. 36 is what percent of 30? 16.8](https://reader036.vdocuments.us/reader036/viewer/2022062410/5697bfbc1a28abf838ca144e/html5/thumbnails/10.jpg)
From 80 to 115
= 0.4375
= 43.75% Write the answer as a percent.
Simplify the numerator.Simplify the fraction.
80 to 115 is an increase, so a change from 80 to 115 is a 43.75% increase.
Find each percent change. Tell whether it is a percent increase or decrease.
![Page 11: Bellwork 1. Find 30% of 40. 2. Find 28% of 60. Solve for x. 3. 22 = x(50) 4. 17.2 = x(86) 5. 20 is what percent of 80? 6. 36 is what percent of 30? 16.8](https://reader036.vdocuments.us/reader036/viewer/2022062410/5697bfbc1a28abf838ca144e/html5/thumbnails/11.jpg)
A. Find the result when 12 is increased by 50%.
0.50(12) = 6 Find 50% of 12. This is the amount of increase.
12 + 6 =18 It is a percent increase, so add 6 to the original amount.
12 increased by 50% is 18.
B. Find the result when 55 is decreased by 60%.
0.60(55) = 33 Find 60% of 55. This is the amount of decrease.
55 – 33 = 22 It is a percent decrease so subtract 33 from the the original amount.
55 decreased by 60% is 22.
![Page 12: Bellwork 1. Find 30% of 40. 2. Find 28% of 60. Solve for x. 3. 22 = x(50) 4. 17.2 = x(86) 5. 20 is what percent of 80? 6. 36 is what percent of 30? 16.8](https://reader036.vdocuments.us/reader036/viewer/2022062410/5697bfbc1a28abf838ca144e/html5/thumbnails/12.jpg)
A. Find the result when 72 is increased by 25%.
0.25(72) = 18 Find 25% of 72. This is the amount of increase.
72 + 18 =90 It is a percent increase, so add 18 to the original amount.
72 increased by 25% is 90.
B. Find the result when 10 is decreased by 40%.
0.40(10) = 4 Find 40% of 10. This is the amount of decrease.
10 – 4 = 6 It is a percent decrease so subtract 4 from the original amount.
10 decreased by 40% is 6.
![Page 13: Bellwork 1. Find 30% of 40. 2. Find 28% of 60. Solve for x. 3. 22 = x(50) 4. 17.2 = x(86) 5. 20 is what percent of 80? 6. 36 is what percent of 30? 16.8](https://reader036.vdocuments.us/reader036/viewer/2022062410/5697bfbc1a28abf838ca144e/html5/thumbnails/13.jpg)
Common application of percent change are discounts and markups.
A discount is an amount by which an original price is reduced.
discount = % of original price
final price = original price – discount
A markup is an amount by which a wholesale cost is increased.
final price = wholesale cost markup+
markup wholesale cost= % of
![Page 14: Bellwork 1. Find 30% of 40. 2. Find 28% of 60. Solve for x. 3. 22 = x(50) 4. 17.2 = x(86) 5. 20 is what percent of 80? 6. 36 is what percent of 30? 16.8](https://reader036.vdocuments.us/reader036/viewer/2022062410/5697bfbc1a28abf838ca144e/html5/thumbnails/14.jpg)
The entrance fee at an amusement park is $35. People over the age of 65 receive a 20% discount. What is the amount of the discount? How much do people over 65 pay?
Method 1 A discount is a percent decrease. So find $35 decreased by 20%.
0.20(35) = 7 Find 20% of 35. This is the amount of the discount.
35 – 7 = 28 Subtract 7 from 35. This is the entrance fee for people over the age of 65.
![Page 15: Bellwork 1. Find 30% of 40. 2. Find 28% of 60. Solve for x. 3. 22 = x(50) 4. 17.2 = x(86) 5. 20 is what percent of 80? 6. 36 is what percent of 30? 16.8](https://reader036.vdocuments.us/reader036/viewer/2022062410/5697bfbc1a28abf838ca144e/html5/thumbnails/15.jpg)
Method 2 Subtract the percent discount from 100%.
100% – 20% = 80% People over the age of 65 pay 80% of the regular price, $35.
0.80(35) = 28 Find 80% of 35. This is the entrance fee for people over the age of 65.
35 – 28 = 7 Subtract 28 from 35. This is the amount of the discount.
By either method, the discount is $7. People over the age of 65 pay $28.00.
![Page 16: Bellwork 1. Find 30% of 40. 2. Find 28% of 60. Solve for x. 3. 22 = x(50) 4. 17.2 = x(86) 5. 20 is what percent of 80? 6. 36 is what percent of 30? 16.8](https://reader036.vdocuments.us/reader036/viewer/2022062410/5697bfbc1a28abf838ca144e/html5/thumbnails/16.jpg)
Helpful Hint
Before solving, decide what is a reasonable answer. For example 3A, a 10% discount is $3.50 off. So a 20% discount would be more than $2 off.
![Page 17: Bellwork 1. Find 30% of 40. 2. Find 28% of 60. Solve for x. 3. 22 = x(50) 4. 17.2 = x(86) 5. 20 is what percent of 80? 6. 36 is what percent of 30? 16.8](https://reader036.vdocuments.us/reader036/viewer/2022062410/5697bfbc1a28abf838ca144e/html5/thumbnails/17.jpg)
A student paid $31.20 for art supplies that normally cost $52.00. Find the percent discount .
$52.00 – $31.20 = $20.80Think: 20.80 is what
percent of 52.00? Let x represent the percent.
The discount is 40%
![Page 18: Bellwork 1. Find 30% of 40. 2. Find 28% of 60. Solve for x. 3. 22 = x(50) 4. 17.2 = x(86) 5. 20 is what percent of 80? 6. 36 is what percent of 30? 16.8](https://reader036.vdocuments.us/reader036/viewer/2022062410/5697bfbc1a28abf838ca144e/html5/thumbnails/18.jpg)
A $220 bicycle was on sale for 60% off. Find the sale price.
Method 2 Subtract the percent discount from 100%.
100% – 60% = 40% The bicycle was 60% off of 100% .
0.40(220) = 88 Find 40% of 220. This is the discount from the original price. 220 – 88 = 142
By this method, the discount is $88. The sale price is $142.00.
![Page 19: Bellwork 1. Find 30% of 40. 2. Find 28% of 60. Solve for x. 3. 22 = x(50) 4. 17.2 = x(86) 5. 20 is what percent of 80? 6. 36 is what percent of 30? 16.8](https://reader036.vdocuments.us/reader036/viewer/2022062410/5697bfbc1a28abf838ca144e/html5/thumbnails/19.jpg)
Ray paid $12 for a $15 T-shirt. What was the percent discount ?
$15 – $12 = $3Think: 3 is what percent of
15? Let x represent the percent.
The discount is 20%.
![Page 20: Bellwork 1. Find 30% of 40. 2. Find 28% of 60. Solve for x. 3. 22 = x(50) 4. 17.2 = x(86) 5. 20 is what percent of 80? 6. 36 is what percent of 30? 16.8](https://reader036.vdocuments.us/reader036/viewer/2022062410/5697bfbc1a28abf838ca144e/html5/thumbnails/20.jpg)
The wholesale cost of a DVD is $7. The markup is 85%. What is the amount of the markup? What is the selling price?
Method 1A markup is a percent increase. So find $7 increased by 85%.0.85(7) = 5.95
7 + 5.95 = 12.95
Find 85% of 7. This is the amount of the markup.
Add to 7. This is the selling price.
Subtract from 12.95. This is the amount of the markup.
12.95 7 = 5.95
By either method, the amount of the markup is $5.95. The selling price is $12.95.
Method 2
Add percent markup to 100%
The selling price is 185% of the wholesale price, 7.
100% + 85% = 185%
Find 185% of 7. This is the selling price.
1.85(7) = 12.95
![Page 21: Bellwork 1. Find 30% of 40. 2. Find 28% of 60. Solve for x. 3. 22 = x(50) 4. 17.2 = x(86) 5. 20 is what percent of 80? 6. 36 is what percent of 30? 16.8](https://reader036.vdocuments.us/reader036/viewer/2022062410/5697bfbc1a28abf838ca144e/html5/thumbnails/21.jpg)
A video game has a 70% markup. The wholesale cost is $9. What is the selling price?
Method 1
A markup is a percent increase. So find $9 increased by 70%.
0.70(9) = 6.30Find 70% of 9. This is the amount
of the markup.
9 + 6.30 = 15.30 Add to 9. This is the selling price.
The amount of the markup is $6.30. The selling price is $15.30.
![Page 22: Bellwork 1. Find 30% of 40. 2. Find 28% of 60. Solve for x. 3. 22 = x(50) 4. 17.2 = x(86) 5. 20 is what percent of 80? 6. 36 is what percent of 30? 16.8](https://reader036.vdocuments.us/reader036/viewer/2022062410/5697bfbc1a28abf838ca144e/html5/thumbnails/22.jpg)
What is the percent markup on a car selling for $21,850 that had a wholesale cost of $9500?
21,850 – 9,500 = 12,350
The markup was 130 percent.
Think: 12,350 is what percent of 9,500? Let x represent the percent.
![Page 23: Bellwork 1. Find 30% of 40. 2. Find 28% of 60. Solve for x. 3. 22 = x(50) 4. 17.2 = x(86) 5. 20 is what percent of 80? 6. 36 is what percent of 30? 16.8](https://reader036.vdocuments.us/reader036/viewer/2022062410/5697bfbc1a28abf838ca144e/html5/thumbnails/23.jpg)