Class: Junior Secondary School 2 (JSS2, JSS 2)
Term: 2nd Term
Week: 1
Age: 13 years
Duration: 45 minutes
Subject: Mathematics
Curriculum Theme: Mathematics
Previous Lesson:
Topic: Expansion of Algebraic Expression
Subject Matter: Expansion of the form a(b + c) = ab + ac, Expansion of the form (a + b)(c + d) = ac + ad + bc + bd with examples and workings

Specific Objectives

By the end of the lesson, pupils should be able to:

Cognitive Domain:
(a) Expand algebraic expressions of the form a(b + c).
(b) Expand algebraic expressions of the form (a + b)(c + d).
Affective Domain:
(a) Appreciate the usefulness of expansion in simplifying algebraic expressions.
Psychomotor Domain:
(a) Carry out expansions correctly using given examples.
Social Domain:
(a) Work cooperatively with peers to solve algebraic expansion problems.

Reference Materials

The following resources was used in planning this lesson:

9 Years Basic Education Curriculum
Lagos State Unified Scheme of Work for Junior Secondary Schools
Math is Fun – “Expanding Brackets” (https://www.mathsisfun.com/algebra/brackets.html)
Relevant Textbooks

Instructional Materials

The teacher will teach this lesson with the aid of:

Algebra charts showing examples of expanded forms
Flash cards with algebraic expressions
Whiteboard and markers
Step-by-step solution worksheets
A multiplication table chart

Rationale for the Lesson

This lesson helps pupils develop foundational algebraic manipulation skills essential for solving higher mathematical problems involving equations and factorization.

Prerequisite/Previous Knowledge

Pupils are already familiar with basic algebraic operations such as addition, subtraction, and multiplication of like terms from previous lessons.

Lesson Content/Board Summary

Expansion of Algebraic Expressions

Expansion of the Form a(b + c) = ab + ac

This form of expansion involves multiplying a single term outside the bracket by each term inside the bracket. This is also called the distributive property of multiplication over addition.

The following are examples:

Expand 2(x + 3)
= 2 × x + 2 × 3
= 2x + 6
Expand 5(a + b)
= 5a + 5b
Expand –3(y – 4)
= –3 × y + (–3 × –4)
= –3y + 12
Expand 7(p + q + r)
= 7p + 7q + 7r

From these examples, we see that every term inside the bracket is multiplied by the term outside the bracket.

Expansion of the Form (a + b)(c + d) = ac + ad + bc + bd

This type of expansion is obtained by multiplying each term in the first bracket by every term in the second bracket.

The following are examples:

Expand (x + 3)(x + 2)
= x(x + 2) + 3(x + 2)
= x² + 2x + 3x + 6
= x² + 5x + 6
Expand (a + 4)(a + 5)
= a(a + 5) + 4(a + 5)
= a² + 5a + 4a + 20
= a² + 9a + 20
Expand (m + 2)(m – 3)
= m(m – 3) + 2(m – 3)
= m² – 3m + 2m – 6
= m² – m – 6
Expand (2x + 1)(x + 4)
= 2x(x + 4) + 1(x + 4)
= 2x² + 8x + x + 4
= 2x² + 9x + 4

These examples show that each term in the first bracket is multiplied by each term in the second bracket, and like terms are then collected to simplify the expression.

Teaching Methods/Instructional Techniques:

Discussion, Lecture, Explanation, Demonstration, Guided Practice, Group Work, Question and Answer

Instructional Procedures

To deliver this lesson, the teacher will adopt the following steps:

Step 1: Introduction

Time: 5 minutes
Teaching Skill: Set Induction
Teacher’s Activity: The teacher revises previous work on multiplication of algebraic terms and asks pupils to recall how to multiply a single term by another term.
Pupils’ Activity: Pupils respond to questions and give examples of multiplication of algebraic terms.
Learning Point: Pupils recall basic algebraic multiplication needed for expansion.

Step 2: Expansion of the Form a(b + c)

Time: 10 minutes
Teaching Skill: Explanation
Teacher’s Activity: The teacher explains and demonstrates how to expand expressions of the form a(b + c) with examples on the board.
Pupils’ Activity: Pupils follow the steps and solve similar problems in their notebooks.
Learning Point: Pupils understand how to expand expressions with a single bracket.

Step 3: Expansion of the Form (a + b)(c + d)

Time: 10 minutes
Teaching Skill: Demonstration
Teacher’s Activity: The teacher shows step-by-step expansion of two brackets using the distributive law, writes examples, and simplifies them.
Pupils’ Activity: Pupils participate actively and attempt similar examples individually or in groups.
Learning Point: Pupils can correctly expand double brackets and simplify expressions.

Step 4: Practice Exercises

Time: 10 minutes
Teaching Skill: Guided Practice
Teacher’s Activity: The teacher gives exercises for pupils to solve individually and monitors their work.
Pupils’ Activity: Pupils solve exercises and ask questions where they face challenges.
Learning Point: Pupils apply learned methods to expand given expressions independently.

Step 5: Note-Taking

Time: 5 minutes
Teaching Skill: Reinforcement
Teacher’s Activity: Teacher dictates or writes the board summary for pupils to copy.
Pupils’ Activity: Pupils write the lesson notes into their notebooks.
Learning Point: Pupils have written reference materials for revision.

Step 6: Evaluation/Review

Time: 3 minutes
Teaching Skill: Questioning
Teacher’s Activity: The teacher evaluates the learning by asking the following questions:

Expand 4(y + 5).
Expand (x + 2)(x + 7).
Expand (a + 3)(a – 5).
Simplify 3(m + n) + 2(m + n).
Pupils’ Activity: Pupils provide answers orally or on the board.
Learning Point: Pupils demonstrate understanding of the two forms of algebraic expansion.

Step 7: Conclusion

Time: 2 minutes
Teaching Skill: Summarization
Teacher’s Activity: Teacher summarizes the main points of the lesson and encourages pupils to practice more problems at home.
Pupils’ Activity: Pupils listen and ask final questions.
Learning Point: Pupils understand how to expand algebraic expressions accurately.

Lesson Keywords

Expansion – multiplying out brackets to remove them
Algebraic Expression – a combination of letters, numbers, and operations
Distributive Law – rule that allows a(b + c) = ab + ac
Term – a single number or variable or a combination of both
Simplify – to make an expression shorter or easier to read

Differentiation

Teacher provides additional examples for struggling learners and uses visual aids to illustrate expansion, while advanced learners solve more complex problems independently.

Note for teachers using this lesson plan

Emphasize step-by-step working to prevent errors. Encourage neatness in writing algebraic expressions and ensure pupils simplify results after expansion.