Teaching sequence

Work through this resource material in the following sequence:

10 minutes

Part A: Introduction - Our plastic addiction

50 minutes

Part B: Understand the problem - Calculating litter at scale

30 minutes

Part C: Design a solution

15 minutes

Part D: Share and reflect

Learning intentions:

Students will:

use a sample area to estimate andunderstand the amount of litter in larger areas.

Success criteria:

Students can:

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.

Part A: Introduction – Our plastic addiction

Step 1

Explain to students that in this lesson, they will be using maths to investigate and design solutions for an environmental problem found in the school and across the country.

Step 2

Watch the following clip as a class (also found on the Student Worksheet). As students watch, invite them to answer the following questions on the Student Worksheet.

What does it mean when they say, “Every little bit does count when we scale it up to the whole population”?
Why would they suggest we make small changes in our everyday lives to stop our plastic addiction?

Plastic addiction - (https://vimeo.com/1056608395/7354e5b897)

Step 3

After watching the clip, discuss with students their responses to the two questions. It may be useful to highlight for students what ‘scale up’ means (i.e. to make something proportionally larger).

Part B: Understand the problem - Calculating litter at scale

Step 1

Explain to students that they will now be looking at the problem of litter at a smaller scale. Specifically, students will be examining the school grounds to see how much litter is in a space of 1m by 1m square. This information will then be used to think about the problem at a larger scale.

In groups of 2-3, students will need a 1m ruler (or a measuring tape) and chalk. Select a small, high-density area in the yard where students will complete this part of the lesson. Consider the amount of time you have to dedicate to this part of the lesson, and ensure you let students know how long they have outside. It would be wise to do this part of the lesson after recess or lunch to get a true representation of the amount of litter in the schoolyard.

Relay the following instructions to students:

Find a spot in the yard and measure out a 1m by 1m square. Mark out the square using chalk or tape.
Count exactly how much litter is in the square (make sure to include any tiny pieces).
Once this is done, throw this litter into a bin and return to the classroom.

Step 2

Once all students have returned to the classroom, get each group to share the amount of litter they have found, and write the numbers on the board. Ask the class: if we measured every 1m by 1m square across the school, how much litter would you expect to see in each square? If needed, prompt students to calculate the mean of the numbers for each group.

Step 3

As a class, go through Part 2 of the Student Worksheet, checking if students are unsure about the meaning of any questions. You can ask students clarifying questions, for example:

What is a Cartesian Plane?
- Suggested answer: A coordinate graph, where a pair of coordinates give each point.
Which one is the x-axis and the y-axis?
- Suggested answer: x-axis is horizontal, y-axis is vertical.
Why doesn’t 1 km² = 1,000m²?
- Suggested answer: 1km² = 1,000m x 1,000m = 1,000,000m²

Step 4

As students work, support them by providing prompts and asking questions, such as:

Can you draw a picture showing the mean number of litter in 1m²? What about 2m²? 3m²? etc.
As an extension for Question 4, ask: can you create an equation to show the amount of litter in any area?

Step 5

As a class, briefly go through the solutions to Part 2 of the Student Worksheet.

Allow calculators if students need them, or to work in pairs.

Part C: Design a Solution

Step 1

As a class, go through Part 3 of the Student Worksheet, checking if students are unsure about the meaning of any questions. Highlight that in Question 3. Students will need to show mathematical working out.

Step 2

As students work, support them by providing prompts and asking questions, such as:

As an extension for Questions 3 and 4, ask: Which are your best two ideas? Can you show what would happen with each of these ideas, and then share your findings?

Allow calculators if students need them, or to work in pairs.

Part D: Share and reflect

Step 1

Get students to share their designs. You can run this in different ways, such as:

Groups share what they’ve done with two or three other groups first. One person is then nominated to share with the whole class.
Each group has 30 seconds to present what they’ve done to the entire class. To make this run efficiently, each student could stand up and present from their desk.

Step 2

Finally, ask students to reflect on what they have learned about proportion. Students can work independently to answer the following questions (also available on the Student Worksheet):

How could you use your graphs to tell if you’d made a mistake in the table of values in Part 2?
Why is it useful to shrink a large problem like litter across Australia to something much smaller (like litter in a space in the yard?)
Why was it more accurate to use the mean amount of litter instead of your group’s amount to understand how much litter there is in larger areas?
What action should we take to reduce the amount of litter in our school?
What action should we take to reduce the amount of litter in Australia?

Assessment

What can the students do, say, make or write?

Students can calculate means, solve a problem involving direct proportion, and convert between units of area. Students can identify solutions to address the issue of litter and apply their solutions mathematically.

Blue - Do the Maths on Litter

Go to

Summary

Learning intentions:

Students will:

Success criteria:

Students can:

Lesson guides and printables

Lesson Details

Skills

Curriculum Mapping

Resources Required

UN Sustainable Development Goals

Additional Info

Related Professional Learning

In this lesson