7th Grade Unit 4: Percents

Percents to Decimals/Decimals to Percents

100

80% as a decimal

0.80

200

0.75 as a percent

75%

300

The percentage left after a 40% decrease, as a decimal

0.60

400

The total percentage after a 30% decrease, as a percent

130%

500

The total percentage after a 150% increase, as a decimal

2.50

Percent Increase/Decrease

100

Last year, there were 50 ducks in the pond. This year, there are 10% less. How many are there now?

45

200

There are 40% more items at the store this year than last year. What percent of last year's number of items are in the store this year?

140%

300

A granola bar company made their bars 15% shorter. If they were 10 cm, how many cm are they now?

8.5 cm

400

The hotel charges a 5% service fee for each night. If the price per night is $100, what would be your total for 2 nights? 

$210

500

Jimbo bought a car for $35,000 last year, and its value is now $28,000. What percent did it decrease by?

20%

Equations

100

Based on the equation c=0.80b, what percent of the original value is the current value?

80%

200

Write an equation to represent a 30% decrease.

c=0.70b or c=(1-0.30)b

300

Write an equation to find the price of a shirt after a 25% off discount. 

c=0.75b or c=(1-0.25)b

400

Desribe a scenario that could match the following equation: c=1.40b

Anything that describes a 40% increase

500

Write an equation to find the number of students in the school if there was a 15% decrease from last year.

c=0.85b or c=(1-0.15)b

Percent Change

100

The percent change between 10 and 15

50%

200

The percent change between 100 and 200

100%

300

The percent change between 25 and 27

8%

400

The percent change between 60 and 100

66.67%

500

The percent change between 300 and 750

150%

Quick Percentages

100

10% of 25

2.5

200

30% of 75

22.5

300

120% of 60

72

400

45% of 200

90

500

86% of 42

36.12