Class: Senior Secondary School 1 (SS1 / SSS 1)
Term: 1st Term
Week: 6
Age: 15 years
Duration: 45 minutes
Subject: Machine Wood Work
Curriculum Theme: Technology
Previous Lesson: Properties Of Timber: Softwood And Hardwood Characteristics.
Topic: Properties of Timber: Characteristics of Softwood and Hardwood.
Subject Matter: Observation of timber properties, Softwood characteristics, Hardwood characteristics.

Specific Objectives

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

Cognitive Domain:

Define timber properties.
List three physical properties of timber.
State four characteristics of softwood.
State four characteristics of hardwood.
Differentiate between softwood and hardwood based on at least two characteristics.

Affective Domain:

Appreciate the importance of understanding timber properties for material selection.
Show interest in observing and identifying different timber types.

Psychomotor Domain:

Identify different timber samples based on their observable properties.
Perform simple observations to distinguish between softwood and hardwood.

Collaborate with peers during the observation of timber samples.

Reference Materials

The following resources were used in planning this lesson:

9 Years Basic Education Curriculum for Technology.
State Unified Scheme of Work for Senior Secondary Schools.
Omolere, S. A. (2018). Woodwork Technology for Senior Secondary Schools. Ibadan: University Press PLC.
https://nigeriancurriculum.gov.ng/
https://www.waeconline.org.ng/e-learning/Woodwork/Woodwork%20SS1%20Q2.pdf

Instructional Materials

The teacher will teach this lesson with the aid of:

Different timber blocks (e.g., pine, iroko, mahogany, spruce).
Weighing scale.
Small containers of water for absorption tests.
Charts showing characteristics of softwood and hardwood.

Rationale for the Lesson

Understanding the properties of timber is important for pupils to select the correct type of wood for various projects. This lesson helps pupils differentiate between softwood and hardwood, enabling them to make informed choices in woodworking and appreciate the natural diversity of timber materials.

Prerequisite/Previous Knowledge

Pupils have basic knowledge of different types of trees and their uses in daily life.

Lesson Content/Board Summary

Properties of Timber: Characteristics of Softwood and Hardwood

Observation of Timber Properties

Timber properties refer to the distinct features and characteristics that describe a specific type of wood. These properties help in identifying, classifying, and determining the suitability of timber for various uses.

The following are physical properties of timber:

Colour: The natural shade of the wood, which can vary widely.
Grain: The pattern formed by the arrangement of wood fibers, which can be straight, wavy, or interlocked.
Texture: The relative size and uniformity of the cells, describing the wood as fine, medium, or coarse.
Density: How heavy the wood is for its size, indicating its compactness.
Hardness: The resistance of the wood to indentation or scratching.
Durability: The ability of the timber to resist decay, insect attack, and wear over time.

Characteristics of Softwood

Softwoods are typically derived from coniferous trees, which are evergreen and have needle-like leaves. Examples include pine, spruce, fir, and cedar.

The following are characteristics of softwood:

They generally come from faster-growing trees.
They are typically lighter in colour.
They are generally less dense and lighter in weight.
They often have prominent growth rings.
They are usually easier to work with tools.
They are commonly used for construction lumber, paper, and general-purpose carpentry.

Characteristics of Hardwood

Hardwoods are typically derived from deciduous trees, which lose their leaves seasonally. Examples include oak, mahogany, teak, iroko, and walnut.

The following are characteristics of hardwood:

They generally come from slower-growing trees.
They are typically darker in colour.
They are generally denser and heavier.
They often have less distinct growth rings.
They are usually harder to work with tools.
They are commonly used for high-quality furniture, flooring, and decorative items due to their durability and aesthetic appeal.

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 name different types of wood they know and where they are used. The teacher then introduces the topic: “Properties of Timber: Characteristics of Softwood and Hardwood.”
Pupils’ Activity: Pupils respond by naming different woods like iroko, mahogany, pine, and their uses in furniture or building.
Learning Point: Pupils are introduced to the lesson topic and connect it to their prior knowledge.

Step 2: Explanation of Timber Properties

Time: 10 minutes
Teaching Skill: Explanation/Definition
Teacher’s Activity: The teacher defines timber properties and explains key physical properties such as colour, grain, texture, density, hardness, and durability, using the timber blocks as examples. The teacher asks pupils to observe these properties in the provided samples.
Pupils’ Activity: Pupils listen, observe the timber blocks, and ask questions for clarification.
Learning Point: Pupils understand what timber properties are and can identify some key physical properties.

Step 3: Observation of Timber Properties

Time: 10 minutes
Teaching Skill: Demonstration/Observation
Teacher’s Activity: The teacher guides pupils to observe the different timber blocks. For example, by holding different blocks to feel their weight (density), scratching them to test hardness, and looking closely at their grain patterns and colours. The teacher may demonstrate a simple water absorption test if feasible.
Pupils’ Activity: Pupils actively observe the timber blocks, feel their weight, observe their colour and grain, and note differences. They may participate in simple tests.
Learning Point: Pupils gain practical experience in observing and comparing timber properties.

Step 4: Characteristics of Softwood

Time: 5 minutes
Teaching Skill: Explanation/Classification
Teacher’s Activity: The teacher presents softwood samples (e.g., pine, spruce) and explains their typical characteristics, such as origin from coniferous trees, faster growth, lighter colour, and common uses. The teacher highlights these features on the board.
Pupils’ Activity: Pupils listen, observe the softwood samples, and note down the characteristics.
Learning Point: Pupils learn and understand the distinct characteristics of softwood.

Step 5: Characteristics of Hardwood

Time: 5 minutes
Teaching Skill: Explanation/Classification
Teacher’s Activity: The teacher presents hardwood samples (e.g., iroko, mahogany) and explains their typical characteristics, such as origin from deciduous trees, slower growth, darker colour, higher density, and common uses. The teacher highlights these features on the board.
Pupils’ Activity: Pupils listen, observe the hardwood samples, and note down the characteristics.
Learning Point: Pupils learn and understand the distinct characteristics of hardwood.

Step 6: Differentiation between Softwood and Hardwood

Time: 3 minutes
Teaching Skill: Comparison/Synthesis
Teacher’s Activity: The teacher facilitates a brief discussion comparing and contrasting softwood and hardwood based on the characteristics discussed. The teacher encourages pupils to state differences.
Pupils’ Activity: Pupils actively participate by stating differences between softwood and hardwood.
Learning Point: Pupils can differentiate between softwood and hardwood based on their properties.

Step 7: Evaluation/Review

Time: 5 minutes

Teaching Skill: Questioning/Assessment

Teacher’s Activity: The teacher evaluates the learning by asking the following questions:

What are timber properties?
Mention three physical properties of timber.
List four characteristics of softwood.
State four characteristics of hardwood.
Differentiate between softwood and hardwood based on two characteristics.

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Pupils demonstrate understanding of the lesson.

Step 8: Conclusion

Time: 2 minutes
Teaching Skill: Summarization/Assignment
Teacher’s Activity: The teacher summarizes the key points of the lesson, emphasizing the importance of knowing timber properties for practical applications. The teacher gives pupils an assignment to find out common uses of two types of softwood and two types of hardwood found in their locality.
Pupils’ Activity: Pupils listen to the summary and copy the assignment.
Learning Point: Pupils consolidate their learning and prepare for further exploration.

Lesson Keywords

Timber – Wood that has been prepared for use in construction or carpentry.
Properties – Distinctive qualities or characteristics of a material.
Softwood – Wood from coniferous trees, generally lighter and easier to work.
Hardwood – Wood from deciduous trees, generally denser and more durable.
Grain – The pattern of fibers in wood.
Density – A measure of how much mass is contained in a given volume; how heavy wood is for its size.

Differentiation

For pupils who grasp concepts quickly, the teacher may ask them to research specific types of timber and their unique properties. For pupils needing more support, the teacher will provide additional labeled samples and simplified explanations, focusing on identifying key differences through hands-on observation.

Note for teachers using this lesson plan

Ensure a variety of timber samples are available for pupils to observe and handle. Encourage tactile and visual exploration during the lesson. Emphasize safety when handling tools or materials, even for simple observations. Adjust the pace based on pupils’ engagement and understanding.