Teaching sequence

Step 1

Begin this activity be presenting students with some paper, aluminium, plastic container and a glass jar. Ask students to analyse each item and describe each material’s appearance.

Now magnify the material. The labelling will look different, but what about the material? For example:

Paper fibres can be seen.
Aluminium will look the same, but there may be some scratches.
Plastic will look the same, but depending on the plastic, scratches might be seen and it may not be as smooth.
Glass should look the same unless it has been heavily worn.
The only material that appears very different is paper.

Ask students to record their answers on the student worksheet.

Step 2

Students will now look at a range of waste materials and how their composition affects the rates at which they decompose. Begin by asking students to watch the following video on sorting recycling (also available on the student worksheet) and identify the types of waste that are being sorted.

Sorting Your Recycling - Video 1 https://vimeo.com/73431280

Ask students to write these types of waste down on the student worksheet. They should list some or all of the following:

Glass bottle
Plastic fizzy drink bottle
Aluminium fizzy drink can
Aerosol/spray can
Tin/steel can
Paper
Milk carton
Plastic bag
Shoe
Clothing

Step 3

Ask student to brainstorm what they know of the terms 'decompose' and 'break down' and write student ideas on the board. Also ask students to think about the following:

How do these words relate to waste and recycling?
What do we mean by decomposition rates or break down rates? (Suggested answer: the time it takes for a material to decompose or break down.)
How does the composition of a material affect the rate at which it will break down? (Suggested answer: objects with highly processed components - like plastics or metals - will take longer to break down. Objects in their natural form - such as food waste - or with lower levels of processing - such as paper - will take less time to break down.)

Step 4

Students will now look at the waste materials identified in the video and work out their decomposition rates from fastest to slowest. The class will be broken into two groups who will compete with each other to order the waste correctly in the fastest time possible.

Print out the worksheet of the types of waste and the rates of break down prior to the activity. Cut along the dotted lines to have two sets, one for each group. Don't let anyone in either group see the actual break down rates until students have attempted to organise the types of waste themselves.

Instructions:

Break the class into two groups. You will need a judge and a time-keeper for each group. The rest of the students in each group should be broken into 12 groups. Assign 10 of the groups with one of the waste materials identified in the video (use the printouts of the worksheets - click here to download). Assign one of the other groups with 'FASTEST' and the other with 'SLOWEST'. Ask someone in each of the 12 groups to hold or stick their label to them.
When ready, ask the first group to go to the front of the classroom. The time-keeper from the opposing team should start the clock and the group should order themselves in a line showing break down rates from fastest to slowest (which ones would break down in the shortest amount of time and which ones would take the longest). The group has one minute to get themselves into the order they think correct.
At the end of the one minute, the group must stop and the judge should then either write down the order they are in or photograph their order as evidence of the order they have chosen.
Repeat for the other group.
The judges from each group should then assess the efforts of each group. Give each of the judges a copy of the actual break down rates (from the printout) and ask them to share with the class where each group went right or wrong.
Finally, working as a class create a new line that shows the correct order of break down rates. Also ask students to write this order down in the student worksheets.

Step 5

Break the class into small groups and ask each group to create a poster or infographic (e.g. Piktochart) that describes what decomposition or break down rates are, and what the break down rates are for the items used in this activity. Students can decide how they want to present this information, but should include:

All the types of waste from this activity as well as banana skins (3-4 weeks), plastic rings from 6-pack (450 years), batteries (100 years), cigarette butt (10 years), and fishing line (800 years);
Text and images; and
Tips on reducing waste.

Assessment/reflection

Ask students to complete the reflection questions on the student worksheet.

Homework/extension

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 should draw what condition they think each item would look like, showing what level of decomposition they might be at. Each item should also be accompanied with a short description that talks about the condition of the item in more detail.

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

Students should present what they have found in a small booklet.

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?

These Planet Ark resources were developed by Cool Australia with funding from the Alcoa Foundation.

National Recycling Week - Break down the Waste

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