Percentages as Proportional Relationships

Percentages II

Creating proportional relationships to solve problems with percents

Proportional Ratios & Percents

What makes an equation proportional?

Multiple Choice

Which expression is proportional?

• $\frac{90\%\ red}{100\%\ total}=\frac{20\ total}{18\ red}$

• $\frac{90\%\ red}{100\%\ total}=\frac{18\ red}{20\ total}$

Multiple Choice

Which expression is proportional?

• $\frac{10\%\ white}{100\%\ total}=\frac{1\ red}{10\ total}$

• $\frac{10\%\ white}{100\%\ total}=\frac{1\ white}{3\ red}$

• $\frac{10\%\ white}{100\%\ total}=\frac{3\ red}{10\ total}$

• $\frac{10\%\ white}{100\%\ total}=\frac{1\ white}{10\ total}$

How do proportions help us find the unknown?

Fill in the Blanks

Find the missing value in this proportion:

 $\frac{3}{4}=\frac{ }{60}$  

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Find the missing value in this proportion:

 $\frac{4}{5}=\frac{56}{ }$  

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Find the missing value in this proportion:

 $\frac{ }{100}=\frac{36}{48}$  

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Find the missing value in this proportion:

 $\frac{7}{8}=\frac{87.5}{ }$  

How to set up percent problems as proportional equation

Multiple Choice

Which proportional relationship best matches the math problem?

What is 30% of 300?

• $\frac{30\%}{100\%}=\frac{300}{ }$

• $\frac{ }{300}=\frac{30\%}{100\%}$

• $\frac{300}{100\%}=\frac{30}{ }$

Multiple Choice

Which proportional relationship best matches the math problem?

20 is ___% of 150

•  $\frac{20\%}{100\%}=\frac{ }{150}$ 

•  $\frac{ }{150}=\frac{20\%}{100\%}$ 

•  $\frac{ }{100\%}=\frac{20}{150}$ 

Multiple Choice

Which proportional relationship best matches the math problem?

___ is 80% of 450

•  $\frac{80\%}{100\%}=\frac{ }{450}$ 

•  $\frac{80\%}{ }=\frac{450}{100\%}$ 

•  $\frac{ }{100\%}=\frac{80}{450}$ 

Reading math problems about percentages

Fill in the Blanks

Your uncle has visited 35 of the 50 U.S. States. What percent of the states has he visited?

Multiple Choice

Which proportional set-up best fits this math question?

Wendy has 4 pets. 3 pets are fish. What percentage of Wendy's pets are fish?

• $\frac{4\ pets}{3\ fish}=\frac{ }{100\%\ pets}$

• $\frac{ }{100\%\ pets}=\frac{1\ not\ fish}{4\ pets}$

• $\frac{3\ fish}{4\ pets}=\frac{ }{100\%\ pets}$

• $\frac{3\ fish}{100\%\ pets}=\frac{ }{4\ pets}$

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Wendy has 4 pets. 3 pets are fish. What percentage of Wendy's pets are fish?

Multiple Choice

Which proportional set-up best fits this math question?

Wendy has 4 pets. 3 pets are fish. What percentage of Wendy's pets are NOT fish?

• $\frac{4\ pets}{3\ fish}=\frac{ }{100\%\ pets}$

• $\frac{ }{100\%\ pets}=\frac{1\ not\ fish}{4\ pets}$

• $\frac{3\ fish}{4\ pets}=\frac{ }{100\%\ pets}$

• $\frac{3\ fish}{100\%\ pets}=\frac{ }{4\ pets}$

Fill in the Blanks

Wendy has 4 pets. 3 pets are fish. What percentage of Wendy's pets are NOT fish?

Multiple Choice

Which proportional set-up best fits the math question?

60% of Peter's friends dress in animal costumes. Peter has 15 friends. How many friends dressed in animal costumes?

• $\frac{60\%\ \cos tume}{100\%\ friends}=\frac{ }{15\ friends}$

• $\frac{15\ friends}{100\%\ friends}=\frac{60\%\ \cos tume}{ }$

• $\frac{15\ friends}{ }=\frac{60\%\ \cos tume}{100\%\ friends}$

Fill in the Blanks

60% of Peter's friends dress in animal costumes. Peter has 15 friends. How many friends dressed in animal costumes?

Multiple Choice

Which proportional set-up best fits the math question?

60% of Peter's friends dress in animal costumes. Peter has 15 friends. How many friends did not dress in costume?

•  $\frac{40\%\ \ no\cos tume}{100\%\ friends}=\frac{ }{15\ friends}$ 

•  $\frac{15\ friends}{100\%\ friends}=\frac{40\%\ no\cos tume}{ }$ 

•  $\frac{ }{15\ friends}=\frac{60\%\ \cos tume}{100\%\ friends}$ 

Fill in the Blanks

60% of Peter's friends dress in animal costumes. Peter has 15 friends. How many friends did not dress in costume?