Activity Introduction

blue_rubbish-plastic-digger-bucket_untitled_1-463-2-edit_photoframeQuick Summary: This lesson incorporates clips from Blue The Film as learning inspiration. Students delve deep into the mathematics behind one of the big environmental problems of today: plastic waste. Students explore what it would mean if we addressed one part of this problem; specifically cutting down on the millions of plastic toothbrushes that are thrown away in Australia each year. This lesson invites students to critically evaluate statistics and use relevant data to calculate the impact of this environmental change.

blue-white-logo-120pxBlue is a feature documentary film charting the drastic decline in the health of our oceans. With more than half of all marine life lost and the expansion of the industrialization of the seas, the film sets out the challenges we are facing and the opportunities for positive change. Blue changes the way we think about our liquid world and inspires the audience to action. Find out how to screen or download the film. Along with the film is an ambitious global campaign to create advocacy and behaviour change through the #oceanguardian movement. To become an ocean guardian, see the website.

Learning intentions: 

  • Students will understand the positive impacts of reducing plastic waste through mathematical investigation. 

21st century skills:


Australian Curriculum Mapping

Content descriptions:

Year 7 Mathematics: Identify and investigate issues involving numerical data collected from primary and secondary sources (ACMSP169)

Syllabus outcomes:  MA4-1WM, MA4-3WM, MA4-19SP.

General capabilities: Critical and Creative Thinking, Ethical Understanding.

Cross-curriculum priority: Sustainability OI.1, OI.6.

Relevant parts of Year 7 Mathematics achievement standards: Students identify issues involving the collection of continuous data. They describe the relationship between the median and mean in data displays.

Topic: Blue The Film, Ocean Conservation, Water, Sustainability.

Unit of work: Blue The Film – Mathematics – Year 7 – 10. 

Time required: 60 mins +

Level of teacher scaffolding: Medium – Lead students in discussion.

Resources required: Student Worksheet – one copy per student. Device capable of presenting a clip to the class. Plastic Statistics Factsheet (one copy per student). Sticky-notes.

Keywords: Blue The Film, ocean conservation, plastic, waste, toothbrushes, investigation, statistics, data.

Cool Australia and Northern Pictures would like to acknowledge the generous contributions of GoodPitch² AustraliaShark Island InstituteDocumentary Australia FoundationThe Caledonia Foundation and Screen Australia in the development of these teaching resources.

Cool Australia’s curriculum team continually reviews and refines our resources to be in line with changes to the Australian Curriculum.

© 2017 Northern Pictures and Cool Australia


Teacher Worksheet

blue_plasticbaglookslikejellyfish_untitled_1-464-1_photoframeTeacher Preparation 

Learning intention: Students will understand the positive impacts of reducing plastic waste through mathematical investigation. 

Success criteria: Students will...

  • Identify and use statistics.
  • Identify the impact we have on our planet.
  • Calculate the impact of cutting back on the amount of toothbrushes we waste each year.


Teacher content information: From space, our planet appears as a tiny blue dot in the vastness of the universe. No matter where you live on our blue planet – you’re connected to the sea.

But the seas are under threat. The industrialisation that has occurred in the oceans over the last century mirrors the events that triggered mass extinctions on land. Industrial scale fishing, habitat destruction, species loss and pollution have placed the ocean in peril. The very nature of the sea is being irretrievably altered.

By international standards, Australia is a marine conservation leader. It has the world’s largest coral reef, the bes

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Student Worksheet

Thought starter: Are you addicted to plastic?

Plastic addiction (

As you watch the clip answer the following questions:

1. What are some of the numbers mentioned in the clip?

2. What do the numbers mean?

The Challenge: 


After reading through the Plastic Statistics Factsheet, answer the questions below:

  1. What is the number of plastic toothbrushes Australians throw away each year? 
  2.  What is half of that amount? 
  3. Write down any statistics from the factsheet that will help you to answer your investigation questions (make sure you can explain why you think each statistic is useful).

Choose one of these impact areas to focus on:

Impact area  Investigation question
 Number of toothbrushes in total  1. If nothing changed, how many plastic toothbrushes would be thrown away by the time you are 30 years old?
2. If we halved the number of plastic toothbrushes that go to waste, how many would be thrown away by the time you are 3
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