Lesson 29

Lesson 29: Advantages and Disadvantages of Waste Decaying

Learning Objective

Understanding that some waste can decay

Syllabus Correlations

· Theme: Investigating Materials

· Learning Area: Waste Management

· Learning Objective: Understanding that some waste can decay

Learning Outcomes:

Pupils should be able to:

· state the advantages of waste decaying.

· state the disadvantages of waste decaying

· predict what will happen to humans and the environment if waste does not decay.

Concept(s) Introduced:

· what are the advantages and disadvantages of waste decaying;

· predict what happens when waste does not decay.

Skills Covered:

· Observing, classifying, making inferences, interpreting data, making conclusions, comparing and contrasting.

Vocabulary/ New Words:

decay, mortar and pestle, organic waste, pollution, recycle, waste

Value(s) Incorporated:

· Having an interest in and curiosity about the environment.

· Being diligent and persevering.

· Realising that science is a means to understand nature.

· Thinking rationally

· Analysing the things around us

Materials Needed:

-

Point(s) to Note:

Explain what are the advantages and disadvantages of waste decaying. Explain effects from waste that does not decay.

Teaching Strategies
Set Induction	Show the video of collections of rubbish. Ask pupils what waste can be identified from the rubbish. Component: Introduction
Step 1	Play the content component. Ask pupils what advantages that waste decaying brings. Teacher explains the advantages to the environment. Teacher introduces a process called composting and show video on how it works. Component : Content 1 Play the content component. Teacher explains what waste takes a long time to decay. Ask pupils what disadvantages waste decaying brings. Ask pupils to describe what happens when organic waste decays, whether it produces odours. Teacher explains the effects of unpleasant odours, poisonous gases and liquid or toxic components from decaying waste. Teacher highlights the effect from waste decaying on oxygen consumption in water. Component: Content 2 Play the content component. Ask pupils what happens when waste does not decay to the environment. Teacher explains its effects on air, water and land pollution. Ask pupils how waste that does not decay attracts pests and subsequently spread diseases. Teacher highlights that health of mankind is also affected. Encourage pupils to take steps in preventing waste from accumulating. Component : Content 3
Step 2	Play the activity component. Ask pupils to drag and drop items according to the right categories. Tell pupils to read the advantages and disadvantages carefully to make correct categorisation. Component: Activity
Step 3	There are five questions in this component covering the learning outcomes. Questions 1 to 3 are objective questions. Q4 is a drag and drop activity. Pupils drag and drop the correct answers for the questions. Q5 consists of true or false questions. Pupils need to identify whether the statements are true or false. Use evaluation sheets to assess the pupils’ understanding of this lesson. Component: Evaluation
Step 4	A project that involves all students that is to make recycled papers. Ask pupils to explain the good use from recycling papers to the environment. Teacher to help pupils to prepare the materials necessary to carry out the project. Guide pupils on the procedure involved using images. Encourage pupils to recycle papers more often. Component: Extension
Conclusion	Conclude the lesson by playing this component to further reinforce understanding of the lesson. Help pupils to identify advantages and disadvantages from waste decaying. Emphasise what happens when waste does not decay. Component : summary