Bell Ringer: 10-20-14images.pcmac.org/SiSFiles/Schools/TX/Alvarado... · 2019. 9. 26. · Weeks 2 4 6 8 Total Savings ($) 60 120 180 240. Time (Minutes) Distance (Miles) 0 0 12 11

Write each decimal as a percent.

1) 0.46

2) 2.47

3) 0.03

4) 5.236

1) 46%

2) 247%

3) 3%

4) 523.6%

Bell Ringer: 10-20-14

1. A machine makes 450 boxes in 20 minutes. Which

expression equals the unit rate in boxes per hour?

A. 450 20

B. 450 1

3

C. 450 20

D. 450 1

3

2. Which rectangle is similar to a rectangle 5 inches wide

and 8 inches long?

A. 18 inches wide and 27 inches long

B. 20 inches wide and 32 inches long

C. 24 inches wide and 32 inches long

D. 30 inches wide and 40 inches long

3. The rectangles are similar. Side AB = 5 and AD = 7.

In the big rectangle, side ML = 4.5. Find side KL.

A. 5.2

B. 6.3

C. 9.5

D. 6.5

4. A map scale is 3 in. : 45 mi. Two cities are 675 miles

apart. How far apart are the cities on the map?

A. 36 inches

B. 2025 inches

C. 45 inches

D. 54 inches

5. The table shows a person saving money at a

constant rate. How much will this person save in 49

days?

A. $210

B. $343

C. $150

D. $120

Weeks 2 4 6 8

Total Savings ($) 60 120 180 240

Time (Minutes) Distance (Miles)

0 0

12 11

15 13.75

30 27.5

45 41.25

6. The table below shows the time it takes a prototype

car to travel different distances. What is the constant

rate of change in this situation in miles per 2 hours?

A. 110 miles per hour

B. 68.75 miles per hour

C. 27.5 miles per hour

D. 55 miles per hour

7. Tim’s mom filled the gas tank in her SUV and spent

$68.00 for 20.5 gallons of unleaded gasoline. What is

the constant of proportionality in this situation?

F. $2.31 per gallon of unleaded gas

G. $3.32 per gallon of unleaded gas

H. $3.16 per gallon of unleaded gas

J. $0.32 per gallon of unleaded gas

8. Ken was pricing ingredients for a recipe he was planning to

make for a dinner party. The store sold 4 different brands of the

same type of product.

Which statement is true about the unit costs of the different

brands?

F. Brand C has a lower unit cost than Brand B.

G. Brand D has a higher unit cost than Brand A.

H. Brand A and Brand C have the same unit cost.

J. Not here

Brand A Brand B Brand C Brand D

8 oz

$2.88

4.5 oz

$1.44

5 oz

$1.50

4 oz

$1.20

9. John’s lost 1.24 kilograms after a week of exercise. If

1 kilogram is approximately 2.5 pounds, about how

many pounds did John lose?

A. 3.74 lb.

B. 3.10 lb.

C. 3.12 lb.

D. 3.64 lb.

10. Susan rides her bicycle 6 miles in 1

4 of an hour. At

this rate, how many miles could she ride in 2 hours?

A. 24 mi.

B. 18 mi.

C. 55 mi

D. 48 mi.

11. Carrie missed 14.3% of the problems on a test. The

test had a total of 105 problems. Which of the following

is the best estimate of the number of problems Carrie

got correct?

A. 95 problems

B. 100 problems

C. 105 problems

D. 90 problems

12. Of the 420 sheep in a flock, 22% are white. What is

the total number of white sheep in the flock?

A. 86 sheep

B. 74 sheep

C. 93 sheep

D. 81 sheep

13. Marty can walk 21

7 miles in 34 minutes. How many

minutes does it take Marty to walk 1 mile?

A. 1611

14

B. 147

8

C. 1513

15

D. 142

7

You go to the store to purchase a bag of dog food that normally costs $16.50. Today it is on sale for 20% off. You also have to pay 8.5% sales tax. How much money do you need in order to buy the dog food?

If you then split the dog food with your friend, how much do each of you have to pay?


Finding Percent Increase

The percent an amount increases or decreases from its original

amount is the percent of change.

Percent increase describes how much a quantity increases in

comparison to the original amount.

Percent of Change =

Percent of Change =

My Favorite Way: (Proportions)

Percent of Change =

Then subtract the original percent from the new percent to find the percent increase.

Amount of Change

Original Amount

New – Old

Old

𝑂𝑟𝑖𝑔𝑖𝑛𝑎𝑙 #

100% =

𝑁𝑒𝑤 #

𝑁𝑒𝑤 𝑃𝑒𝑟𝑐𝑒𝑛𝑡

Find the percent increase from 10 to 12

1st: Find amount of increase:

12 – 10 = 2

2nd: set up fraction.

Percent of increase = amount of change

original amount

0.2 =

Divide to find

the decimal.

Move decimal

2 places to the

right

Percent

increase from

10 to 12 is

20%

20% 12 −10

10 =

2

10 =

Step 1: 10

100% =

12

____%

Step 2: 120% - 100%

20%



7 – 5 = 2



original amount

0.4 =

Divide to find

the decimal.

Move decimal 2

places to the

right

Percent

increase from

5 to 7 is 40%

40% 7 −5

5 =

2

5 =

Step 1: 5

100% =

7

____%

Step 2: 140% - 100%

40%



12 – 2 = 10



original amount

5 =

Divide to find

the decimal.

Move decimal 2

places to the

right

Percent

increase from

2 to 12 is

500%

500% 12 −2

2 =

10

2 =

Step 1: 2

100% =

12

____%

Step 2: 600% - 100%

500%

Find the percent increase from 4 to 7.5


7.5 – 4 = 3.5



original amount

0.875 =

Divide to find

the decimal.

Move decimal 2

places to the

right

Percent

increase from

4 to 7.5 is

87.5%

87.5% 7.5 −4

4 =

3.5

4 =

Step 1: 4

100% =

7.5

____%

Step 2: 187.5% - 100%

87.5%

Now You Try: Find each percent increase.

From 100 to 114

From 2.0 to 3.2

From 4,000 to 8,500

14%

60%

112.5%

114 −100

100 =

3.2 −2

2 =

8,500 −4,000

4,000 =

14

100 =

1.2

2 =

4,500

4,000 =

.14 =

.6 =

1.125 =

Step 1: 100

100% =

114

____%

Step 2: 114% - 100%

14%

Step 1: 2

100% =

3.2

____%

Step 2: 160% - 100%

60%

Step 1: 4000

100% =

8500

____%

Step 2: 212.5% - 100% 112.5%

Find each percent increase.

• From 50 to 75

• From 2.0 to 3.5

• From 8,000 to 16,400

50%

75%

105%


The annual production of video games in

the United States has more than doubled

since the 1960s. Find the percent increase

from 1960 to 1990.

Year Number of Video

Games Produced

1960 88,000

1990 205,000

Percent of increase from 1960-1990 was about 133%.

205,000 −88,000

88,000 =

117,000

88,000 = 1.329 = 132.9%

Step 1: 88000

100% =

205000

____%

Step 2: 232.95% - 100%

132.95%

Finding Percent Decrease Percent Decrease describes how much a quantity decreases in

comparison to the original amount.

Percent Decrease is found the SAME way that Percent of Increase is.

1st: Find amount of decrease:

(Greater # – Smaller #) = Amount of Change

2nd: Set up your fraction:

3rd: Divide and move decimal 2 places to the right.

My Favorite Way: (Proportions)

Percent of Change =

Now subtract the new percent from the original percent in order to get your answer.

amount of change

original amount

𝑂𝑟𝑖𝑔𝑖𝑛𝑎𝑙 #

100% =

𝑁𝑒𝑤 #

𝑁𝑒𝑤 𝑃𝑒𝑟𝑐𝑒𝑛𝑡

Find the percent decrease from 12 to 9


12 – 9 = 3


Percent of decrease = amount of change

original amount

0.25 =

Divide to find

the decimal.

Move decimal 2

places to the

right

Percent

decrease from

12 to 9 is 25%

25% 12 −9

12 =

3

12 =

Step 1: 12

100% =

9

____%

Step 2: 100% - 75%

25%



10 – 8 = 2



original amount

0.2 =

Divide to find

the decimal.

Move decimal 2

places to the

right

Percent

decrease from

10 to 8 is 20%

20% 10 −8

10 =

2

10 =

Step 1: 10

100% =

8

____%

Step 2: 100% - 80%

20%



125 – 115 = 10



original amount

0.08 =

Divide to find

the decimal.

Move decimal 2

places to the

right

Percent

decrease from

125 to 115 is

8%

8% 125 −115

125 =

10

125 =

Step 1: 125

100% =

115

____%

Step 2: 100% - 92%

8%

Find the percent decrease from 65 to 35.75


65 – 35.75 = 29.25



original amount

0.45 =

Divide to find

the decimal.

Move decimal 2

places to the

right

Percent

decrease from

65 to 35.75 is

45%

45% 65 −35.75

65 =

29.25

65 =

Step 1: 65

100% =

35.75

____%

Step 2: 100% - 55%

45%

Now Your Turn: Find the percent decrease to the nearest

whole percent.

From 9.6 to 4.8

From 202 to 192

From 854.5 to 60.6

50%

5%

93%

9.6 −4.8

9.6 =

4.8

9.6 = 0.5 =

202 −192

202 =

10

202 = 0.0495 =

854.5 −60.6

854.5 =

793.9

854.5 = 0.9290 =

Step 1: 9.6

100% =

4.8

____%

Step 2: 100% - 50%

50%

Step 1: 202

100% =

192

____%

Step 2: 100% - 95%

5%

Step 1: 854.5

100% =

60.6

____%

Step 2: 100% - 7%

93%

A computer that costs $875 last year costs $745 this

year. Find the percent decrease to the nearest whole

percent.

14.85% = 875 −745

875 =

130

875 = 0.1485 = 15%

Step 1: 875

100% =

745

____%

Step 2: 100% - 85%

15%


Using Percent of Change • Given an original amount and a percent increase or

decrease, you can use the percent of change to find the new

amount.

Ex. The grizzly bear population in Yellowstone National Park

in 1970 was about 270. Over the next 35 years, it increased by

about 115%. What was the population in 2005?

Step 1: 270 𝐵

100% =

? 𝐵

215%

Step 2: 270 x 2.15

580.5 Bears = 581 Bears

Documents

Bell Ringer: 10-20-14images.pcmac.org/SiSFiles/Schools/TX/Alvarado... · 2019. 9. 26. · Weeks 2 4 6 8 Total Savings ($) 60 120 180 240. Time (Minutes) Distance (Miles) 0 0 12 11