Class: Senior Secondary School 1 (SS1 / SSS 1)
Term: 1st Term
Week: 8
Age: 15 years
Duration: 45 minutes
Subject: Machine Wood Work
Curriculum Theme: Technology
Previous Lesson: Properties Of Timber: Differences Between Softwood And Hardwood.
Topic: Properties of timber Physical properties of common west African timbers
Subject Matter: Physical properties of Abura, Physical properties of Mahogany, Physical properties of Iroko, Physical properties of Opepe

Specific Objectives

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

Cognitive Domain:

Define physical properties of timber.
State the physical properties of Abura timber.
State the physical properties of Mahogany timber.
State the physical properties of Iroko timber.
State the physical properties of Opepe timber.

Affective Domain:

Appreciate the importance of identifying different timber types by their physical properties.
Show interest in learning about various West African timbers.

Psychomotor Domain:

Identify samples of Abura, Mahogany, Iroko, and Opepe timbers.
Compare the physical properties of the different timber samples.

Work cooperatively in groups to observe and discuss 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.
Akinyemi, O. (2010). Woodwork for Senior Secondary Schools. University Press PLC.
https://www.waeconline.org.ng/
https://www.nerdc.gov.ng/

Instructional Materials

The teacher will teach this lesson with the aid of:

Samples of Abura wood
Samples of Mahogany wood
Samples of Iroko wood
Samples of Opepe wood
Whiteboard/Blackboard and markers/chalk

Rationale for the Lesson

Understanding the physical properties of different timbers helps pupils to select the correct wood for specific projects and applications. This knowledge also enables pupils to identify and differentiate between common West African timbers, which is important for practical woodwork activities and future careers.

Prerequisite/Previous Knowledge

Pupils have basic knowledge of timber as a material and may have seen different types of wood used around them.

Lesson Content/Board Summary

Physical Properties of Common West African Timbers

Physical Properties of Timber

Physical properties of timber are characteristics that can be observed or measured without changing the chemical composition of the wood. These properties help in identifying and selecting timber for various uses.

Physical Properties of Abura

Abura is a common West African timber with distinct physical properties:

Colour: Light reddish-brown.
Grain: Generally straight.
Texture: Medium to fine.
Hardness: Moderately hard.
Durability: Moderately durable.
Workability: Easy to work with hand and machine tools.

Physical Properties of Mahogany

Mahogany is a well-known timber valued for its appearance and workability:

Colour: Reddish-brown, darkening with age.
Grain: Often interlocked or wavy.
Texture: Medium to coarse.
Hardness: Moderately hard.
Durability: Durable to very durable.
Workability: Good workability, finishes well.

Physical Properties of Iroko

Iroko is a popular timber used as a substitute for Teak due to its properties:

Colour: Yellowish-brown, darkening to a rich brown with exposure.
Grain: Often interlocked.
Texture: Coarse.
Hardness: Hard.
Durability: Very durable and resistant to insect attack.
Workability: Can be difficult to work due to its hardness and interlocked grain, but finishes well.

Physical Properties of Opepe

Opepe is another important West African timber, known for its strength and durability:

Colour: Golden-yellow to orange-brown.
Grain: Often interlocked.
Texture: Medium to coarse.
Hardness: Hard.
Durability: Very durable, especially in exposed conditions.
Workability: Moderately difficult to work due to its hardness.

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 reviews the previous lesson briefly. The teacher then introduces the new topic by asking pupils to mention different types of wood they know and what makes them different.
Pupils’ Activity: Pupils respond to the teacher’s questions and share their knowledge of different wood types.
Learning Point: Pupils recall prior knowledge and are introduced to the lesson topic.

Step 2: Presentation of Abura Timber

Time: 8 minutes
Teaching Skill: Explanation/Demonstration
Teacher’s Activity: The teacher presents a sample of Abura wood, explains its physical properties (colour, grain, texture, hardness, durability, workability) and writes key points on the board. The teacher guides pupils to observe the sample.
Pupils’ Activity: Pupils observe the Abura wood sample, listen to the explanation, and note down the properties.
Learning Point: Pupils learn and record the physical properties of Abura timber.

Step 3: Presentation of Mahogany Timber

Time: 8 minutes
Teaching Skill: Explanation/Demonstration
Teacher’s Activity: The teacher presents a sample of Mahogany wood, explains its physical properties, and writes key points on the board. The teacher encourages pupils to compare it with the Abura sample.
Pupils’ Activity: Pupils observe the Mahogany wood sample, listen to the explanation, note down the properties, and make comparisons.
Learning Point: Pupils learn and record the physical properties of Mahogany timber and begin comparing.

Step 4: Presentation of Iroko Timber

Time: 8 minutes
Teaching Skill: Explanation/Demonstration
Teacher’s Activity: The teacher presents a sample of Iroko wood, explains its physical properties, and writes key points on the board. The teacher highlights notable differences from previous timbers.
Pupils’ Activity: Pupils observe the Iroko wood sample, listen to the explanation, note down the properties, and participate in discussion.
Learning Point: Pupils learn and record the physical properties of Iroko timber.

Step 5: Presentation of Opepe Timber

Time: 8 minutes
Teaching Skill: Explanation/Demonstration
Teacher’s Activity: The teacher presents a sample of Opepe wood, explains its physical properties, and writes key points on the board. The teacher asks pupils to identify its unique features.
Pupils’ Activity: Pupils observe the Opepe wood sample, listen to the explanation, note down the properties, and identify unique features.
Learning Point: Pupils learn and record the physical properties of Opepe timber.

Step 6: Evaluation/Review

Time: 5 minutes

Teaching Skill: Questioning/Assessment

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

What are physical properties of timber?
Mention three physical properties of Abura timber.
State two differences between Mahogany and Iroko timber based on their physical properties.
Describe the typical colour of Opepe timber.

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Pupils demonstrate understanding of the lesson.

Step 7: Conclusion

Time: 3 minutes
Teaching Skill: Summarization
Teacher’s Activity: The teacher summarizes the lesson by reiterating the importance of knowing the physical properties of different timbers for proper selection and use. The teacher assigns homework for pupils to research other common West African timbers.
Pupils’ Activity: Pupils listen to the summary and copy down the homework.
Learning Point: Pupils consolidate their understanding and are encouraged to further explore the topic.

Lesson Keywords

Abura – A light reddish-brown West African timber with straight grain and moderate hardness.
Mahogany – A reddish-brown timber with interlocked grain, known for good workability.
Iroko – A hard, very durable yellowish-brown timber with coarse, interlocked grain.
Opepe – A hard, very durable golden-yellow to orange-brown timber with interlocked grain.
Physical properties – Characteristics of timber observable without changing its chemical composition.
Grain – The arrangement or direction of wood fibres.
Texture – The relative size and distribution of wood cells, influencing its feel.
Durability – The resistance of timber to decay and insect attack.

Differentiation

For pupils who grasp concepts quickly, the teacher can challenge them to identify additional properties or research specific uses for each timber. For pupils needing extra support, the teacher can provide simplified notes or pair them with faster learners for peer instruction and hands-on observation of the timber samples.

Note for teachers using this lesson plan

Ensure that actual samples of each timber (Abura, Mahogany, Iroko, Opepe) are available and accessible for pupils to touch and observe. Encourage pupils to describe what they see and feel. Emphasize safety when handling wood samples, especially if they have rough edges.