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 perform an analysis of and design solutions to combat one of our major environmental issues; litter. Students use a study of a local site at school to calculate the amount of litter at a larger scale. Proportional thinking is embedded in a meaningful problem that students themselves can address.

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 here. 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 intention:

  • Students will be able to use a sample area to estimate and understand the amount of litter in larger areas.

21st century skills:


Australian Curriculum Mapping

Content descriptions:

Year 9 Mathematics

  • Solve problems involving direct proportion. Explore the relationship between graphs and equations corresponding to simple rate problems (ACMNA208)

Syllabus outcomes: MA5.2-1WM, MA5.2-2WM, MA5.2-5NA

General capabilities: Critical and Creative Thinking, Ethical understanding.

Cross-curriculum priority: Sustainability OI.6, OI.7.

Relevant parts of Year 9 achievement standards: Students calculate relative frequencies to estimate probabilities.

Topic: Blue The Film, Ocean Conservation, Water.

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

Time required: 110 min +

Level of teacher scaffolding: Medium – oversee activities and lead students in discussion.

Resources required: Student Worksheet – one copy per student. Device capable of presenting a clip to the class. Tape measures or metre rulers – one per group of 2-3 students, chalk or tape – one per group of 2-3 students, calculators – one per student (optional).

Keywords: Blue The Film, ocean conservation, litter, sample.

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_rubbish-waste-beach_anhang-1-copy_photoframeTeacher Preparation

Learning intention: Students will be able to use a sample area to estimate and understand the amount of litter in larger areas.

Success criteria: Students will...

  • Be able to calculate means, solve a problem involving direct proportion, and convert between units of area.
  • Know that litter is a huge problem, both on land and in the ocean.


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

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Student Worksheet

Thought starter: Does a little bit of litter go a long long way?

Part 1: Introduction – Our Plastic Addiction

Watch the following clip as a class and answer the questions below. 

Plastic addiction (

1. What does it mean when they say, “Every little bit does count when we scale it up to the whole population”?

2. Why would they suggest we make small changes in our everyday lives to stop our plastic addiction?

Part 2: Understand the Problem - Calculating Litter at Scale

1. The number of pieces of litter my group found in 1m²?

2.  The mean number of pieces of litter each group in the class found in 1m²=

For Questions 3-7, use the mean number from Question 2 to do any calculations.

3.  Fill in the table of values below, by assuming that all areas have the same proportion of litter as what you found in Question 2 (i.e. 1m² = mean number of pieces of litter).

Area 1m² 2m² 3m² 4m² 5m² 10m² 999m²
Number of pieces of litter    
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