Independent Quizizz on Proportions

Proportions

​

Vocabulary: Ratio

A comparison of 2 or more things

The previous slide was notes!

​Please make sure to copy the vocabulary word and definition into your notebook

Go back to the previous slide and copy the definition of a ratio into your composition book. (Leave an empty page if we didn't finish putting the rotaiton notes into your composition book.)

Some text here about the topic of discussion

Multiple Choice

Write the ratio as a fraction in simplest form. 
 
  24 players : 3 teams

• 8:3

• 8 to 1

• 8/1

• 8/3

​You simplify a ratio the same way you simplify a fraction.

In the previous example we divided both values by 3

Subject | Subject

Some text here about the topic of discussion

Multiple Choice

Write the ratio as a fraction in simplest form.
15 girls to 6 boys   

• 5 to 2

• 5/3

• 3 to 5

• 5/2

Multiple Choice

The class has 12 girls and 16 boys. What is the ratio of total students to boys? (simplest form)

• 28/16
• 7/4
• 16/28
• 12/16

Multiple Choice

The pet store has 18 dogs toys for sale. 10 toys are frisbees and the rest are bones. What is the ratio of bones to frisbees in simplest form?

• 5/9
• 8/10
• 4/5
• 18/10

Vocabulary: Proportion

Ratios that are equal

The previous slide was notes!

​Please make sure to copy the vocabulary word and definition into your notebook

Go back to the previous slide and copy the definition of a ratio into your composition book. (Leave an empty page if we didn't finish putting the rotaiton notes into your composition book.)

Some text here about the topic of discussion

Multiple Choice

Determine whether each pair of ratios forms a proportion

• Proportion

• Not a Proportion

Since the ratios are equal they are in proportion

Some text here about the topic of discussion

Solve proportions by cross multipling

then solve the algebra equation !

Multiple Choice

$$\frac{x}{5}=\frac{8}{10}$$  

• x=7

• x=4

• x=2

• x=3

Multiply 10 and x and multiply 8 and 5 so ....

10x = 40

so ....

x = 4

​Cross Multiply

You may have been able to simply think about this and figured out the value of x. As the problems get more involved mental math will work less.

​Mental Math

Some text here about the topic of discussion

Multiple Choice

$$\frac{4}{5}=\frac{8}{x}$$  

• x = 8

• x = 10

• x = 4

• x = 5

Multiple Choice

Solve the proportion below:

• 42

• 6

• 2

• 28

Multiple Choice

Solve the proportion below:

• 3

• 24

• 21

• 12

Multiple Choice

$$\frac{5}{x}=\frac{10}{14}$$  

• 5

• 6

• 7

• 28

The equations for the last 3 problems should have been

7x = 14(3) 6c = 7(18) 10x = 5(14)

7x = 42 6c = 126 10x = 70

Calculating?

Solving the previous 3 problems mentally is fantastic - but look at the equations briefly anyways!

​Mental Math

Did you use mental math?

Some text here about the topic of discussion

When solving a proportion with an algebraic expression - make sure to use the distributive propery

The previous slide was notes!

​Please make sure to copy the example into your notebook

Go back to the previous slide and copy the definition of a ratio into your composition book. (Leave an empty page if we didn't finish putting the rotaiton notes into your composition book.)

Some text here about the topic of discussion

Finish solving this proportion.....

b =

Multiple Choice

9b = 7b - 70

b = ?

• 5

• -35

• 7

• -140

Multiple Choice

Solve the equation for x:

• x = -1/4

• x = 1/3

• x = -3/4

• x = 3/4

11(x-5) = 7(x-8)

11x - 55 = 7x - 56

4x - 55 = -56

4x = -1

x = -1/4

​Algebra Work

Cross Multiply

Distribute

Subtract 7x to both sides

Add 55 to both sides

Divide by 4

​Steps

Some text here about the topic of discussion

Multiple Choice

Solve for w

• 10/3

• 50/9

• 46/9

• 22/3

8(6) = 9(w-2)

48 = 9w - 18

+18 + 18

66 = 9w

w = 66/9 or 22/3 when simplified

​Algebra Work

Cross Multiply

Distribute

Add 18 to both sides

Divide by 9

​Steps

Some text here about the topic of discussion

Multiple Choice

Solve the equation for x:

• 17

• 16

• 15

• 14

Multiple Choice

Solve for x

• 1/2

• 25/8

• 11

• 53/4

Proportions are frequently used to solve real life problems

Writing a proportion to solve a problem

• The man's height will be in proportion to the tree's height

• The man's shadow will be in proportion to the tree's shadow

• Now you can solve the problem

• As long as the corresponding parts are matched up

Multiple Choice

x =

• 5

• 7

• 10

• 14

Multiple Choice

To find the height of a very tall pine tree, you measure your shadow and the tree's shadow.  How tall is the tree?

• 144 feet

• 72 feet

• 36 feet

Multiple Choice

To find the height of a very tall pine tree, you measure your shadow and the tree's shadow. What proportion is correct?

• 
  

  $$\frac{6}{2}=\frac{24}{x}$$

• $$\frac{6}{x}=\frac{2}{24}$$
  

• $$\frac{6}{x}=\frac{24}{2}$$
  

You can also write proportions for the corresponding sides of similiar triangles

​Notice that the corresponding sides are NOT equal....but they are in proportion

The previous slide was notes!

​Please make sure to copy the words and the example into your notebook

Some text here about the topic of discussion

Multiple Choice

The two right triangles below are similar. What side corresponds with AC

• DF

• EF

• DE

Multiple Choice

The two right triangles below are similar. AC corresponds with DF , $$\frac{AC}{DF}$$ , and DE corresponds with?

• AC

• CB

• AB

Multiple Choice

The two right triangles below are similar. So the correct proportion is ...

• $$\frac{CB}{FE}=\frac{AB}{DE}$$

• $$\frac{AC}{CB}=\frac{DF}{DE}$$

• $$\frac{AC}{DE}=\ \frac{AB}{DF}$$

Multiple Choice

The two right triangles below are similar. So the correct proportion is ...

• $$\frac{5}{9}=\frac{13}{x}$$

• $$\frac{12}{9}=\frac{13}{x}$$

• $$\frac{5}{13}=\ \frac{9}{x}$$

Multiple Choice

The two right triangles below are similar. What is x, the length of DE?

• 3.75

• 9.75

• 10

• 12

Multiple Choice

Write a proportion and find the length of the missing side

• 5

• 7

• 9

• 11

Great Job