Week 9 Mathematics Lesson Note JSS 2 – Introduction To Probability

Subject: Mathematics
Class: Junior Secondary School 2 (JSS 2)
Term: Third Term
Week: 9
Topic: Probability
✍️ Written by: Mrs. Emily Bolujo – The Sovereign Educator | Lessonshabitat.com

—

LESSON TITLE: Understanding Basic Probability
DURATION: 40 minutes – 1 hour
CURRICULUM STANDARD: Nigerian NERDC Curriculum for Mathematics (JSS2 – Week 9)

—

Learning Objectives:
By the end of the lesson, students should be able to:

Define probability in simple terms.
Identify the possible outcomes of an event.
Calculate the probability of an event using fractions.
Apply probability to real-life situations (e.g. tossing coins, selecting names, drawing cards).

—

Keywords:

Probability
Outcomes
Likelihood
Event
Impossible
Certain
Fraction
Experiment

—

✳️ SET INDUCTION (Story-Based Introduction):

“Chinedu and Amina were playing a game of chance during break time. They took a coin and agreed: ‘If it lands on HEADS, I win, if it lands on TAILS, you win.’ As they played, Chinedu noticed something — sometimes he won, sometimes he lost. He asked, ‘Is there a way to know how likely I am to win?’”

Teacher to class: “If you were Chinedu, how would you measure your chances of winning? That, my children, is the power of probability — a tool to understand chances in life and math.”

—

ENTRY BEHAVIOUR:

The teacher asks:

“Who has played a game with dice before?”
“When you pick a card from a shuffled deck, do you know which one you’ll get?”
Learners are allowed to share brief experiences.

—

TEACHING METHODS & RESOURCES:

Interactive discussion
Practical demonstrations (coins, dice, colored papers)
Board work
Activity sheets

—

LESSON EXPLANATION:

1. What is Probability?
Probability is the measure of how likely an event is to happen.

2. Common Probability Words:

Certain (It must happen)
Likely (It may happen)
Unlikely (It probably won’t happen)
Impossible (It can never happen)

3. Calculating Probability:
Formula:
Probability of an event =
Number of favourable outcomes ÷ Total number of possible outcomes

Example 1:
If you toss a coin, there are 2 possible outcomes: Head or Tail.
What is the probability of getting a Head?
Answer: 1 ÷ 2 = ½

Example 2:
A bag contains 3 red balls and 2 blue balls. What is the probability of picking a red ball?
Total balls = 5
Red balls = 3
Probability = 3 ÷ 5 = ⅗

4. Real-Life Examples in Nigeria:

Tossing a coin before a football match
Selecting a prefect’s name from a hat
Drawing a lucky number in a raffle draw
Guessing the gender of a newborn baby (boy or girl)

—

CLASS ACTIVITY:

Provide each group with:

1 coin
1 dice
Small colored papers (red, blue, green)

Instructions:

Toss the coin 10 times. Record how many times Head appears.
Roll the dice 12 times. Record how many times number “4” shows.
Pick one colored paper randomly without looking. Return and repeat 10 times. Record color outcomes.

Each group calculates the probability of each result.

—

‍ TEACHER-PUPIL INTERACTION (Sample Dialogue):

Teacher: “If I roll a fair die, what’s the chance I’ll get number 7?”
Student: “Number 7 doesn’t exist on a die!”
Teacher: “Exactly! So the probability is…?”
Class: “Zero! Impossible!”
Teacher: “Excellent. That’s how probability helps us reason logically.”

—

BOARD SUMMARY:

Event	Favourable Outcome	Total Outcome	Probability
Tossing a coin (get Head)	1	2	½
Picking red from 3 red, 2 blue	3	5	⅗
Rolling a die (get 3)	1	6	⅙

Part A: 15 Fill-in-the-Gap Questions (With Options)

The probability of an event happening is always between ______ and ______.
A. 0 and 2
B. 0 and 10
C. 0 and 1
D. 1 and 100
Answer: C
If you toss a fair coin, the probability of getting a Head is ______.
A. 1
B. ½
C. 0
D. 2
Answer: B
Probability deals with ______ of events happening.
A. addition
B. subtraction
C. likelihood
D. length
Answer: C
An event that will never happen is said to be ______.
A. possible
B. likely
C. certain
D. impossible
Answer: D
The total number of outcomes when tossing a die is ______.
A. 5
B. 6
C. 10
D. 12
Answer: B
A bag contains 3 red balls and 2 blue balls. The probability of picking a red ball is ______.
A. ⅗
B. ½
C. ⅖
D. 2⁄3
Answer: A
If a coin is tossed once, there are ______ possible outcomes.
A. 1
B. 2
C. 3
D. 4
Answer: B
A certain event has a probability of ______.
A. 0
B. ½
C. 1
D. 10
Answer: C
If an event is impossible, its probability is ______.
A. 0
B. ½
C. 1
D. 2
Answer: A
A die has ______ faces.
A. 4
B. 5
C. 6
D. 7
Answer: C
If a student randomly selects a day from a week, the probability of choosing Monday is ______.
A. 1/5
B. 1/6
C. 1/7
D. 1/3
Answer: C
A bag contains 4 white beads and 1 black bead. The probability of picking the black bead is ______.
A. 1/2
B. 1/5
C. 2/5
D. 4/5
Answer: B
Events that cannot happen at the same time are called ______ events.
A. impossible
B. equal
C. separate
D. mutually exclusive
Answer: D
A probability of ½ means the event is ______.
A. certain
B. impossible
C. equally likely to occur or not occur
D. not likely
Answer: C
In probability, the number of outcomes that favor an event is called the ______ outcome.
A. false
B. favourable
C. average
D. equal
Answer: B

—

Part B: 10 Evaluation Questions

What is probability?
If you roll a die, what is the probability of getting number 2?
Give an example of an impossible event.
A box contains 5 blue pens and 5 red pens. What is the probability of picking a red pen?
If you toss a coin twice, what are the possible outcomes?
List three examples of real-life activities that involve probability.
What is the difference between a certain and an unlikely event?
A pupil picks one fruit from a basket containing only mangoes and oranges. What is the probability of picking a mango?
What is meant by the total number of possible outcomes in an event?
Why is probability useful in everyday life?

—

Part C: 10 Frequently Asked Questions (FAQs) about Probability for JSS 2

Q: What is probability in simple words?
A: Probability is the chance of something happening. It tells us how likely an event is to occur.
Q: Can probability be more than 1?
A: No, probability is always between 0 (impossible) and 1 (certain).
Q: What is the meaning of “favourable outcome”?
A: It is the outcome you are hoping or looking for in an experiment.
Q: Is tossing a coin a fair way to decide something?
A: Yes, because each side (Head or Tail) has an equal chance of appearing.
Q: How many outcomes does a die have?
A: A die has 6 outcomes: 1, 2, 3, 4, 5, and 6.
Q: What does a probability of ½ mean?
A: It means the event has an equal chance of happening or not happening.
Q: Can a probability be written as a percentage?
A: Yes. For example, ½ = 50%.
Q: What is the probability of getting an even number on a die?
A: There are 3 even numbers (2, 4, 6), so the probability = 3/6 = ½.
Q: What are some real-life examples of probability?
A: Tossing a coin, drawing raffle tickets, weather forecasts, picking a colored card from a bag.
Q: How do we know if an event is impossible?
A: If it can never happen — like rolling a 7 on a 6-sided die — then it is impossible (probability = 0).

—

EVALUATION QUESTIONS:

Define probability.
If a die is rolled, what is the probability of getting a 5?
A bag contains 4 blue balls and 1 green ball. What is the probability of picking a green ball?
What is the probability of getting a tail when a coin is tossed?
What is the meaning of “impossible” in probability?
List two real-life events that involve probability.
What is the total number of outcomes in tossing a coin?
Why must probability be between 0 and 1?
Can the probability of an event be more than 1? Explain.
If 3 out of 10 students picked mango juice, what’s the probability a student picked mango?

—

ASSIGNMENT:

Draw a table showing all the possible outcomes of rolling a dice and tossing a coin once.
Solve: A bag has 2 red pens, 3 blue pens, and 5 green pens. What is the probability of picking a blue pen?

—

HOME CONNECTION:

Ask your parent or guardian to help you observe an event at home where chance is involved — like picking a spoon from a set, guessing what’s for dinner, or flipping a coin. Write down the outcomes and describe the probability!

—

SEO Block (for lessonshabitat.com)

Focus Keyword: Probability
SEO Title: Week 9 Mathematics Lesson Note JSS 2 – Introduction to Probability
Slug: jss2-mathematics-week9-probability-lesson-note
Meta Description: Explore this EEAT-optimized Mathematics lesson note on Probability for JSS 2, Week 9. Includes Nigerian classroom examples, practical activities, and probability calculations