what does it mean to say… “60% of the cars in the parking lot are blue”?
TRANSCRIPT
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
1
Let’s Review
Simplifying ratios
4 : 20
2 : 10
1 : 5
20
4
10
2
5
1
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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