What does it mean to say…“60% of the cars in the parking lot are

blue”?

In this lesson you will learn to define percents by using ratios.

Ratios show how two (or more) quantities are related.

Let’s Review

Part-to-total ratio: 1 pink sweater for every 5 total sweaters

Let’s Review

The ratio of pink sweaters to total sweaters is…

1 to 5 1:55

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Let’s Review

Simplifying ratios

4 : 20

2 : 10

1 : 5

20

4

10

2

5

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Let’s ReviewA Common Mistake

Confusing 60% and 60

60% of the cars ≠ 60 of the cars

Let’s ReviewCore Lesson

60% of the cars in the parking lot are blue.

60% = 60 percent

for every 10060% = 60

A percent is a part-to-total ratio where the second number is always 100.

Let’s ReviewCore Lesson

60% of the cars in the parking lot are blue.

60 for every 100 total cars are blue.

60 out of 100 total cars are blue.

The ratio of blue cars to total cars is 60:100.

The ratio of blue cars to total cars is 100

60

100 = total number of cars60 = part that are blue

Let’s ReviewCore Lesson

60% of the cars in the parking lot are blue.

60 out of 100 total cars are blue.

100

60 _2

_2

_10

_10

50

30

=5

3

=

30 out of 50 total cars are blue.

3 out of 5 total cars are blue.

In this lesson you have learned to define percents by using

ratios.

Let’s ReviewGuided Practice

Which is NOT equivalent to 30% ?a. 30 out of 100b. 30:100c. 10 out of 30d. 3 for every 10

Let’s ReviewExtension Activities

60% of the cars in the parking lot are blue.

Write a part-to-part ratio that describes this situation. What does the second number in your ratio mean?

Let’s ReviewExtension Activities

Write 59% as a ratio in three different ways.

Let’s ReviewQuick Quiz

Which is NOT equivalent to 25% ?

Write 7% as a ratio in three different ways.

a. 25:100

b. 100 for every 25

c. 5 out of 20

d.

4

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