1. Everything
you need to
know about
in grade 6
Probability

2. (The chance of something happening)
Probability
(The chance of something happening)
Certain (100% sure it will happen)
Likely (Large chance it will happen)
Possible (It may or may not happen)
Unlikely (Small chance it will happen)
Impossible
(100% sure it
will not happen)

3. There are 2
kinds of
probability
experimental
probability
theoretical
probability

4. Experimental Probability (Based on the results of an experiment)
For example:
When rolling a die five
times, what is the
experimental probability
of getting a six?
So, in this case…
the experimental
probability of getting
a six is
2 or 40% 5
Out of my 5 tests,
I rolled a six twice

5. Theoretical Probability (Based on all the possible outcomes) So…
The theoretical
probability of getting
a six is 1 6
For example:
When rolling a die,
what is the
theoretical probability
of getting a six?
Rolling a 6 is
one out of six
possible outcomes

6. Theoretical Probability We can also determine all possible outcomes
in situations with
multiple factors.

7. When I go out for dinner with my family, I get to order an
For example:
When I go out for dinner with
my family, I get to order an
appetizer, main dish, and
dessert.
The appetizers on
tonight‘s menu are garden
salad or mushroom soup.
The main dishes are beef stew,
lasagna, or grilled chicken.
The desserts are fruit salad
or sorbet.
List all the possible meal
combinations.

8. I can lay out all my options in a TREE DIAGRAM
I can follow the branches of my diagram
to see all my possible combinations.
I will list my appetizer options first.
I can count the items in the right column
to know the amount of choices I have.
Next, I will list my main dish options.
Last, I will list my dessert options.
I count 12 possible choices.
Fruit Salad
Beef Stew
Sorbet
Garden
Salad
Fruit Salad
Lasagna
Sorbet
Grilled Chicken
Fruit Salad
Sorbet
Fruit Salad
Beef Stew
Sorbet
Mushroom
Soup
Fruit Salad
Lasagna
Sorbet
Grilled Chicken
Fruit Salad
Sorbet

9. There are 12 possible choices
If all I wanted to know was
how many possible
combinations there were,
I could have created a table
I could then multiply together
the amount of choices in
each category to determine
the total number of
possible combinations
2 x 3 x 2 = 12
There are 12 possible choices 2
choices X 3
choices X 2
choices
Appetizers
Main Dishes
Desserts
Garden Salad
Beef Stew
Fruit Salad
Mushroom Soup
Lasagna
Sorbet
Grilled
Chicken

10. Let’s see if you can answer some probability questions…
Sam actually only got
heads once
Did he do anything wrong?
If Sam flipped a coin ten times,
how many times would
you expect him to get heads?
No he didn’t!
Experimental probability
can be different from theoretical probability.
Even though it is unlikely that
Sam would only get heads once,
it is still possible.
Right!
You would expect him to get heads 5 times, because the theoretical probability
of getting heads is 1/2
and 5/10 = 1/2

11. 8/25 or 32% Let’s see if you can answer some probability questions…
We surveyed our class to find out about ice cream preferences.
12 preferred vanilla
8 preferred chocolate
5 didn’t like ice cream at all.
Each student writes his/her
name on a slip of paper and
puts it in a bag.
What are the chances of drawing the name of a student who prefers chocolate ice cream?
8/25 or 32%

12. Thanks for watching!