Warm Up

1
Warm Up
Problem of the Day
Lesson Presentation
2
Warm Up Write each fraction as a decimal and as a
percent. 1. 2. 3. 4.
0.75 75
0.50 50
0.375 37.5
3
Problem of the Day What fraction of the numbers
from 0 to 99 are divisible by 3?
4
Learn to estimate the likelihood of an event and
to write and compare probabilities.
5
Insert Lesson Title Here
Vocabulary
probability
6
Probability is the measure of how likely an event
is to occur.
7

• Probabilities are written as fractions or
  decimals from 0 to 1 or as percents from 0 to
  100. The higher an events probability, the more
  likely that event is to happen.
• Events with a probability of 0, or 0,
  never happen.
• Events with a probability of 1, or 100, always
  happen.
• Events with a probability of 0.5, or 50, have
  the same chance of happening as of not
  happening.

8
Impossible Unlikely As likely as not
Likely Certain
9
Insert Lesson Title Here
Additional Example 1 Estimating the Likelihood
of an Event Write impossible, unlikely, as likely
as not, likely, or certain to describe each
event. A. You roll an even number on a standard
number cube. B. February has 28 days.
as likely as not
certain
10
Insert Lesson Title Here
Additional Example 1 Estimating the Likelihood
of an Event Write impossible, unlikely, as likely
as not, likely, or certain to describe each
event. C. This spinner lands on blue. D. This
spinner lands on an odd number.
unlikely
impossible
11
Insert Lesson Title Here
Check It Out Example 1 Write impossible,
unlikely, as likely as not, likely, or certain to
describe each event. A. You guess a number
between 1 and 1,000. B. You will roll an odd
number on a standard number cube.
unlikely
as likely as not
12
Insert Lesson Title Here
Check It Out Example 1 Write impossible,
unlikely, as likely as not, likely, or certain to
describe each event. C. This spinner lands on
green. D. This spinner lands on an even number.
unlikely
certain
13
Insert Lesson Title Here
Additional Example 2 Writing Probabilities A.
The weather report gives a 75 chance of snow.
Write this probability as a decimal and as a
fraction.
75 0.75
B. The chance of being chosen is 0.8. Write this
probability as a fraction and as a percent.
0.8 80
14
Insert Lesson Title Here
Additional Example 2 Writing Probabilities C.
There is a chance of getting a ring. Write
this probability as a decimal and as a percent.
15
Insert Lesson Title Here
Check It Out Example 2 A. The weather report
gives a 25 chance of snow. Write this
probability as a decimal and as a fraction.
25 0.25
B. The chance of being chosen is 0.6. Write this
probability as a fraction and as a percent.
0.6 60
16
Insert Lesson Title Here
Check It Out Example 2 C. There is a chance
of getting a ring. Write this probability as a
decimal and as a percent.
17
Insert Lesson Title Here
Additional Example 3A Comparing Probabilities
On a standard number cube, there is a 50 chance
of rolling a multiple of 2 and a 33 chance
of rolling a multiple of 3. Is it more
likely to roll a multiple of 2 or a multiple of
3?
It is more likely to roll a multiple of 2.
18
Insert Lesson Title Here
Additional Example 3B Comparing
Probabilities When you spin a certain spinner,
there is a 15 chance that it will land on
yellow, a 15 chance it will land on green, and a
70 chance that it will land on purple. Is it
more likely to land on purple or on green?
Compare 70 gt 15
It is more likely to land on purple than on green.
19
Insert Lesson Title Here
Check It Out Example 3A When you spin a certain
spinner, there is a 25 chance that it will land
on purple, a 35 chance it will land on green,
and a 40 chance that it will land on red. Is it
more likely to land on red or on green?
Compare 40 gt 35
It is more likely to land on red than on green.
20
Insert Lesson Title Here
Check It Out Example 3B When you spin a certain
spinner, there is a 9 chance that it will land
on yellow, a 35 chance it will land on
brown, and a 55 chance that it will land
on blue. Is it more likely to land on brown or on
yellow?
It is more likely to land on brown than on yellow.
21
Insert Lesson Title Here
Lesson Quiz
Write impossible, unlikely, as likely as not,
likely, or certain to describe each event. 1. The
sun will rise tomorrow. 2. You will roll 13
when rolling two dice. 3. There is a 0.125 chance
of picking the winning ticket. Write this
probability as a fraction and as a percent. 4.
At Hamburger Hut, there is a 20 chance of
getting a plastic dinosaur cup and a 35
chance of getting a plastic rabbit cup. It is
less likely that you will receive a rabbit cup
or dinosaur cup?
certain
impossible
dinosaur cup