Class: Primary 3
Term: 2nd Term
Week: 9
Age: 8 years
Duration: 45 minutes
Subject: Mathematics
Curriculum Theme: Mathematics
Previous Lesson: Length and Perimeter of Plane Shapes.
Topic: Perimeter and Area of Plane Shapes
Subject Matter: SHAPES, Concept of perimeter of plane shapes, Concept of area of plane shapes

Specific Objectives

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

Cognitive Domain:

Define plane shapes, perimeter, and area.
Identify various plane shapes such as squares and rectangles.
State the formulas for calculating the perimeter and area of squares and rectangles.
Differentiate between perimeter and area, including their units of measurement.

Affective Domain:

Appreciate the importance of perimeter and area in measuring real-life objects.
Show willingness to accurately measure and calculate.

Psychomotor Domain:

Calculate the perimeter of given squares and rectangles.
Calculate the area of given squares and rectangles.

Participate in group activities to solve measurement problems.

Reference Materials

The following resources were used in planning this lesson:

9 Years Basic Education Curriculum
State Unified Scheme of Work
New General Mathematics for Primary 3

Instructional Materials

The teacher will teach this lesson with the aid of:

Ruler
Measuring tape
Cut-out shapes (square, rectangle)
Real-life objects (e.g., exercise book, table surface)
Whiteboard/Chalkboard
Markers/Chalk

Rationale for the Lesson

This lesson helps pupils understand how to measure the distance around and the surface covered by flat objects. This knowledge is important for everyday tasks like fencing a garden or knowing how much paint is needed for a wall.

Prerequisite/Previous Knowledge

Pupils should be familiar with basic plane shapes (square, rectangle) and simple measurement concepts.

Lesson Content/Board Summary

Perimeter and Area of Plane Shapes

SHAPES

Plane shapes are flat shapes that can be drawn on a piece of paper. They have two dimensions: length and width.

The following are common plane shapes:

Square
Rectangle
Triangle
Circle

Concept of Perimeter of Plane Shapes

Perimeter is the total distance around the edge of a plane shape.

Formula for a Square:

Perimeter (P) = side + side + side + side

P = 4 × side

Formula for a Rectangle:

Perimeter (P) = length + width + length + width

P = 2 × (length + width)

Units of Perimeter: Centimetres (cm), Metres (m), Kilometres (km).

Worked Examples: Perimeter

Example 1: Find the perimeter of a square with a side of 5 cm.

Step 1: Write the formula: P = 4 × side

Step 2: Substitute the value: P = 4 × 5 cm

Step 3: Calculate: P = 20 cm

Example 2: A rectangle has a length of 8 m and a width of 3 m. Find its perimeter.

Step 1: Write the formula: P = 2 × (length + width)

Step 2: Substitute the values: P = 2 × (8 m + 3 m)

Step 3: Add inside the bracket: P = 2 × 11 m

Step 4: Calculate: P = 22 m

Concept of Area of Plane Shapes

Area is the amount of surface covered by a plane shape.

Formula for a Square:

Area (A) = side × side

Formula for a Rectangle:

Area (A) = length × width

Units of Area: Square centimetres (cm²), Square metres (m²), Square kilometres (km²).

Worked Examples: Area

Example 1: Find the area of a square with a side of 5 cm.

Step 1: Write the formula: A = side × side

Step 2: Substitute the value: A = 5 cm × 5 cm

Step 3: Calculate: A = 25 cm²

Example 2: A rectangle has a length of 8 m and a width of 3 m. Find its area.

Step 1: Write the formula: A = length × width

Step 2: Substitute the values: A = 8 m × 3 m

Step 3: Calculate: A = 24 m²

Difference between Perimeter and Area of Plane Shapes

Perimeter: Measures the distance around the edge of a shape. Its units are linear (e.g., cm, m).

Area: Measures the space or surface inside a shape. Its units are square units (e.g., cm², m²).

Teaching Methods/Instructional Techniques

Discussion, Lecture, Demonstration, Question and Answer, Visual Aids

Instructional Procedures

Step 1: Introduction

Time: 5 minutes
Teaching Skill: Set Induction
Teacher’s Activity: The teacher greets the pupils and asks them to identify different plane shapes (e.g., the classroom board, a book cover). The teacher then asks how they would measure the edge of the board or the surface of the book.
Pupils’ Activity: Pupils identify shapes and suggest ways to measure them.
Learning Point: Pupils are introduced to the concept of measuring around and covering shapes.

Step 2: Concept of Perimeter

Time: 10 minutes
Teaching Skill: Explanation/Demonstration
Teacher’s Activity: The teacher defines perimeter as the distance around a shape. Using a cut-out square, the teacher demonstrates how to measure each side and add them up to find the perimeter. The teacher then introduces the formulas for the perimeter of a square and a rectangle and works through one example on the board.
Pupils’ Activity: Pupils listen, observe the demonstration, and copy the definition and example into their notes.
Learning Point: Pupils understand what perimeter is and how to calculate it for squares and rectangles.

Step 3: Concept of Area

Time: 10 minutes
Teaching Skill: Explanation/Demonstration
Teacher’s Activity: The teacher defines area as the amount of surface inside a shape. Using a cut-out rectangle, the teacher explains how to find the area by multiplying its length and width. The teacher introduces the formulas for the area of a square and a rectangle and works through one example on the board.
Pupils’ Activity: Pupils listen, observe, and copy the definition and example into their notes.
Learning Point: Pupils understand what area is and how to calculate it for squares and rectangles.

Step 4: Comparison of Perimeter and Area & Units

Time: 10 minutes
Teaching Skill: Discussion/Comparison
Teacher’s Activity: The teacher leads a discussion on the differences between perimeter and area, focusing on what each measures and their different units (cm vs cm², m vs m²). The teacher provides another example where pupils calculate both the perimeter and area of a single shape (e.g., a rectangle) to highlight the distinction.
Pupils’ Activity: Pupils participate in the discussion, answer questions, and solve the combined example.
Learning Point: Pupils can differentiate between perimeter and area and understand the correct units for each.

Step 5: Evaluation/Review

Time: 7 minutes
Teaching Skill: Questioning/Assessment
Teacher’s Activity: The teacher evaluates the learning by asking the following questions:

What is a plane shape?
Define perimeter.
State the formula for the area of a square.
A rectangular field is 10 m long and 6 m wide. Calculate its perimeter and area.

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Pupils demonstrate understanding of the lesson.

Step 6: Conclusion

Time: 3 minutes
Teaching Skill: Summarization
Teacher’s Activity: The teacher summarizes the key points of the lesson, emphasizing that perimeter is the distance around and area is the surface covered. The teacher assigns homework, which includes calculating the perimeter and area of various shapes from their textbook.
Pupils’ Activity: Pupils listen to the summary and copy down their homework.
Learning Point: Pupils recall the main concepts of perimeter and area.

Home Task: Solve three new exercises on Perimeter and Area of Plane Shapes. Show each step and check each answer.

Lesson Keywords

Perimeter – The distance around the outside edge of a shape.
Area – The amount of surface inside a shape.
Plane shapes – Flat shapes like squares and rectangles.
Square – A plane shape with four equal sides.
Rectangle – A plane shape with four sides, where opposite sides are equal.
Units – Standards for measuring, like cm, m, cm², m².

Differentiation

For struggling learners, the teacher will provide pre-drawn shapes with measurements and guide them step-by-step through calculations. Advanced learners will be given more complex shapes or real-life scenarios to measure and calculate, such as finding the missing side given the perimeter or area.

Note for teachers using this lesson plan

Ensure pupils have access to rulers or measuring tapes for hands-on activities. Emphasize the difference in units for perimeter (linear) and area (square) from the beginning. Use visual aids and real-life examples to make the concepts more relatable and easier for Primary 3 pupils to grasp.