Class: Junior Secondary School 2 (JSS2, JSS 2)
Term: 1st Term
Week: 6
Age: 13 years
Duration: 45 minutes
Subject: Mathematics
Curriculum Theme: Mathematics
Previous Lesson: Addition, Subtraction, Multiplication and Division of Directed Numbers
Topic: Inverse Identity
Subject Matter: Additive and Multiplicative inverse, Use of inverse operation solving simple equations.

Specific Objectives

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

Cognitive Domain:
(a) Identify the additive and multiplicative inverse of given numbers.
(b) Apply inverse operations in solving simple algebraic equations.
Affective Domain:
(a) Develop interest and confidence in solving inverse operation problems.
Psychomotor Domain:
(a) Solve examples involving inverse operations correctly on the board.
Social Domain:
(a) Collaborate with classmates to practice inverse problems and share ideas.

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
Cuemath – “Inverse Operations and Their Uses” (https://www.cuemath.com/algebra/inverse-operations/)
Relevant Textbook’s

Instructional Materials

The teacher will teach this lesson with the aid of:

Number charts showing positive and negative integers
Flashcards with inverse operation examples
Whiteboard and markers
Simple algebraic equation cards
Visual aids showing arithmetic symbols (+, −, ×, ÷)

Rationale for the Lesson

This lesson helps students understand how numbers and operations relate through their inverses, a key skill for solving equations and simplifying algebraic expressions.

Prerequisite/Previous Knowledge

Pupils already know basic arithmetic operations—addition, subtraction, multiplication, and division—and have solved simple equations in earlier classes.

Lesson Content/Board Summary

Inverse Identity: Additive and Multiplicative Inverse

Additive Inverse

The additive inverse of a number is another number that, when added to it, gives zero as the result. It is the “opposite” of a number on the number line.

Examples include:

The additive inverse of +5 is −5, because (+5) + (−5) = 0.
The additive inverse of −12 is +12, because (−12) + (+12) = 0.
The additive inverse of 0 is 0, because zero added to itself remains zero.

The following are important points about additive inverse:

Every real number has an additive inverse.
The sum of a number and its additive inverse is always zero.

Multiplicative Inverse

The multiplicative inverse of a number is the number that, when multiplied by it, gives one as the result. It is also called the reciprocal.

Examples include:

The multiplicative inverse of 4 is 1/4, because 4 × 1/4 = 1.
The multiplicative inverse of 2/3 is 3/2, because (2/3) × (3/2) = 1.
The multiplicative inverse of −5 is −1/5, because (−5) × (−1/5) = 1.

The following are key points about multiplicative inverse:

Every number except zero has a multiplicative inverse.
The product of a number and its multiplicative inverse is always one.

Use of Inverse Operation in Solving Simple Equations

Inverse operations are opposite mathematical operations used to isolate variables and solve equations.
Addition and subtraction are inverses of each other, while multiplication and division are inverses of each other.

The following are examples:

Solve x + 7 = 12
Subtract 7 from both sides: x = 12 − 7 = 5.
Solve 3x = 9
Divide both sides by 3: x = 9 ÷ 3 = 3.
Solve x/4 = 6
Multiply both sides by 4: x = 6 × 4 = 24.

Inverse operations help in checking solutions by performing the opposite operation to confirm correctness.

Teaching Methods/Instructional Techniques:

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

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 reviews the previous lesson on basic arithmetic operations and asks pupils what happens when they add or subtract opposite numbers.
Pupils’ Activity: Pupils respond by giving examples like 5 + (−5) = 0.
Learning Point: Pupils recall and connect the idea of opposite numbers to inverses.

Step 2: Additive Inverse

Time: 10 minutes
Teaching Skill: Explanation
Teacher’s Activity: The teacher defines additive inverse and gives examples using positive and negative numbers.
Pupils’ Activity: Pupils listen, take notes, and provide examples of additive inverses.
Learning Point: Pupils understand that the sum of a number and its additive inverse is zero.

Step 3: Multiplicative Inverse

Time: 10 minutes
Teaching Skill: Discussion
Teacher’s Activity: The teacher explains multiplicative inverse and demonstrates with integers and fractions.
Pupils’ Activity: Pupils state examples and verify by multiplying pairs of inverses.
Learning Point: Pupils learn that the product of a number and its multiplicative inverse is one.

Step 4: Use of Inverse Operation in Solving Simple Equations

Time: 10 minutes
Teaching Skill: Demonstration
Teacher’s Activity: The teacher solves examples of equations using inverse operations and guides pupils to do similar exercises.
Pupils’ Activity: Pupils practice solving equations using inverse operations in pairs.
Learning Point: Pupils apply inverse operations to find unknown values in simple equations.

Step 5: Note-Taking

Time: 5 minutes
Teaching Skill: Explanation
Teacher’s Activity: The teacher writes the board summary and instructs pupils to copy it neatly.
Pupils’ Activity: Pupils copy the board summary into their notebooks.
Learning Point: Pupils have accurate notes 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:

What is the additive inverse of −8?
What is the multiplicative inverse of 2/5?
Solve for x: 4x = 12.
Solve for y: y − 3 = 9.
Pupils’ Activity: Pupils answer orally and on the board.
Learning Point: Pupils demonstrate understanding of inverse identities and equation solving.

Step 7: Conclusion

Time: 2 minutes
Teaching Skill: Reinforcement
Teacher’s Activity: The teacher summarizes the main points and encourages pupils to practice inverse operations regularly.
Pupils’ Activity: Pupils listen and ask questions for clarification.
Learning Point: Pupils appreciate the importance of inverse identities in mathematics.

Lesson Keywords

Inverse – opposite operation or value that undoes another
Additive inverse – number that gives zero when added to another
Multiplicative inverse – number that gives one when multiplied by another
Equation – a mathematical statement showing two expressions are equal
Reciprocal – another term for multiplicative inverse

Differentiation

Teacher gives step-by-step guidance for slower learners, provides additional examples for average learners, and assigns challenging inverse problems for fast learners.

Note for teachers using this lesson plan

Always demonstrate with practical examples and use number lines for visual clarity. Ensure pupils check their answers by reversing the operations.