Teaching Sequence

Part A: Understanding Waste Breakdown

Step 1.

Introduce this activity to your students by holding a brief discussion about waste. Use the following questions to engage students (suggested answers include):

What is waste and where does it come from? – Stuff that we no longer want, such as packaging, unwanted household or industrial items, or leftover food.
What happens to waste and where does it go? – Some types of waste break down quickly (like paper or fresh food) but other types of waste can take a very long time to break down, and so may stay in our environment for years and years.
Why is it a problem? – A lot of waste is slow to break down. When left in our environment it can be the source of terrible pollution and environmental damage. Also, when some types of waste break down they release chemicals that are harmful to our environment.
Can students think of any examples of waste causing serious environmental problems? - The Great Pacific Garbage Patch, pollution of freshwater sources such as rivers and lakes, environmental damage from landfill sites leaching contaminants.

Step 2.

Ask students to think about the breakdown or decomposition of waste (includes suggested answers):

What does decomposition mean? – It means the breaking down or rotting of materials into smaller and smaller parts.
Where does something go when it has decomposed? – It becomes part of the natural environment.
How do things decompose? – Most organic items (items made from natural materials) decompose with the help of tiny animals or microorganisms. Some chemical materials never decompose.

Step 3.

Lay the Waste breakdown flashcards out on the floor explaining that these are common types of waste that are produced by households. Ask students to think about how long each item will take to decompose or break down. Working as a class, ask students to arrange the cards into a line showing the waste item with the shortest breakdown time at one end, and the one with the longest breakdown rate at the other end. Ask students not to turn over the cards until everyone in the class is happy with the order of the line.

Step 4.

When the line is complete ask students to turn the cards over and talk about how their guesses correspond with the actual breakdown rates:

Which ones did they get right?
Which ones did they get wrong?
Why do they think some things take so long and others are pretty quick? You will notice that the more natural an item is the faster it will break down, but greater levels of manufacturing or processing will probably mean the item will take longer to break down (for example the banana is very fast as it is a natural material but the tin cans have been created through a heavy manufacturing process so will take much longer even though are created from tin which is a natural substance). Some items will break down evenly while others will have bits and pieces that are faster or slower to break down (for example the leather on the leather boot might be faster than the eyelets for the laces or the plastic soles).

Step 5.

Ask students to rearrange the cards so that they are in the correct order. Answers below:

Banana - 3-4 weeks
Tin cans - 200-500 years
Plastic rings from six pack - 450 years
Sock - 1 year
Leather boot - 40-50 years
Paper bag - 1 month
Glass bottles - unknown

Part B: Imagining Waste Breakdown

Step 1.

Ask students to imagine that they are archeologists working 100 years in the future. They have been asked to excavate the kitchen of an Australian house that was buried by mud when a river burst its banks during a big storm. It’s the job of the students to record the condition of items that are found there. Students can draw the items or create them with modelling clay. Students should try to show how the items look and at what level of decomposition they might be. Each item should also be accompanied by a label or short description that talks about the condition of the item in more detail and why it's at its current level of decomposition.

Ask students to ‘find’ and describe the following items:

Plastic salad bowl
Wooden chopping board
Packet of chocolate biscuits
Bag of coffee beans
Ceramic teapot
Knife and fork
Water glass
Box of cereal
Kitchen sink
Tea towel

Step 2.

Once complete, invite students to share their 'findings' with a peer and to compare the similarities and differences in their findings.

Reflection

Invite students to work independently to reflect on what they found out in this lesson. Students could answer the following questions in writing or through discussion, depending on age and ability:

What did this lesson make you think about waste?
How was the information presented in this lesson connected to what you already knew?
What information was new to you?
How do you now feel about the waste in your lunchbox?

Through this process ensure that students understand that they alone are not responsible for 'fixing' the waste problem. Waste is an issue that requires action from all sectors of society: from the individuals who make choices about the products they buy and the ways they dispose of waste to the companies who make the products that may become waste to governments who can make laws about how products are made and what happens to waste. The waste issue is something for all of us to work together on!

Take It Further

The lesson Clean Up Australia - Buried Waste: Foundation also explores how waste breaks down and could be used to explore this topic more deeply with students.

Teacher Reflection

Take this opportunity to reflect on your own teaching

What did you learn about your teaching today?
What worked well?
What didn't work so well?
What would you share?
Where to next?
How are you going to get there?

Clean Up Australia - Waste Breakdown Game

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