Class VII

Certain, Impossible and In-Between

Lesson

In What could happen? we looked at how we can keep track of all the different outcomes in an experiment. Now we are going to look at some special words that we use to describe the likelihood or chance that an event or result will occur.

Remember!

These are $5$5 key terms used to describe chance:

Impossible: definitely will NOT happen.
Unlikely: more likely NOT to happen than to happen.
Even chance: equally likely to happen as not to happen.
Likely: more likely to happen than not to happen.
Certain: definitely will happen.

Worked examples

Question 1

What is the chance that next week will have $8$8 days?

Impossible
A
Likely
B
Unlikely
C
Certain
D
Even chance
E

Question 2

A game in a classroom uses this spinner.

A colorful spinner is divided into four equal sectors, each with a numerical value and a distinct color. Starting from the top-left and moving clockwise, the first sector is blue with the number $4$4, followed by an orange sector with the number $7$7, a purple sector with the number $5$5, and finally a green sector with the number $6$6. From the center, a white arrow points to the lower right.

What is the chance of spinning an $odd$ number?
certain
A
even chance
B
impossible
C
likely
D
What is the chance of spinning a $2$2?
likely
A
impossible
B
certain
C
even chance
D
What is the chance of spinning a number less than $8$8?
likely
A
impossible
B
even chance
C
certain
D

Question 3

Order the following events from least likely to most likely with the numbers $1$1 (least likely) to $5$5 (most likely).

$\editable{}$ $Winning the lottery$

$\editable{}$ $A house that is randomly chosen has an odd street number$

$\editable{}$ $Rolling a $7$ 7 on a standard die$

$\editable{}$ $The sun will rise tomorrow$

$\editable{}$ $Rolling more than $1$ 1 on a standard die$

Outcomes

7.DH.DH.4

Feel of probability using data through experiments. Notion of chance in events like tossing coins, dice etc. Tabulating and counting occurrences of 1 through 6 in a number of throws. Comparing the observation with that for a coin.Observing strings of throws, notion of randomness.