Many school lunch items are packaged into single serves for perceived convenience but have a greater impact on our environment and the family budget. This activity will help students think about alternatives.

Learning objective

Students work in pairs to calculate the volume and cost of using one large box of sultanas versus one multi-pack.

Curriculum links

Mathematics; Measurement and geometry

Using units of measurement

Cross-curriculum priority: Sustainability

General capabilities

• Literacy
• Numeracy
• Critical and creative thinking
• Personal and social capability

Keywords

Bulk, single serve, volume, cost saving

Background information

This lesson explores how buying in bulk can save families money and avoid packaging waste.

A waste-free lunch contains no single-use packaging. Food and drinks are packed in reusable containers within a reusable lunch bag or box. All containers are resealable so that leftover food and drink can be consumed (or composted) later.

Holding a waste-free lunch day is a great way to:

• reduce food and packaging waste in your school
• help students and parents understand the benefits of a waste-free lunch
• educate and inspire students and the wider school community to avoid and recover waste.

Resources required

One large box of sultanas

One multi-pack of sultanas

Activity

• Working in pairs, students compare the large box and multi-pack of sultanas:
  • Which packet looks the biggest?
  • Record the total mass (weight) of sultanas in each packet: Which packet contains the most sultanas?
  • Calculate the total packaging used for each packet (area). Consider the total paper and total plastic used. Some students find it helpful to pull apart the packaging. Which packet contains the most packaging waste?
  • Calculate the cost per serve for each type of packaging. Make sure the serving sizes are the same.
  • Which packet gives you the best value for money?
• Students work out the cost savings for their family per year, based on bringing one serve of sultanas per day to school.
• Discuss with students why is it a good idea to buy items in bulk rather than individually packaged, including:
  • less waste from packaging
  • buying in bulk is cheaper
  • sending a message to manufacturers to use less packaging
  • how to bring the sultanas to school from the large box
  • other foods that come in single serves but could be bought in bulk and brought to school in reusable containers.

Taking it further

• Using online supermarket prices, students explore prices for their favourite food items which can be bought in single serves and bulk.
• Make a class chart that compares the cost per 100g serve of the students’ favourite foods bought in bulk compared to single serves. Share this with parents.
• Look at ingredients/nutrition labels on food items to explore food miles, nutritional/health value, and sustainability of ingredients.
• Investigate the costs and nutritional content of fresh fruit and vegetables compared to packaged food. Use your school’s waste wise garden to compare the cost of growing your own to buying. Share this with parents at a morning tea, with the costings and health information displayed on each type of food.
• Brainstorm other packaging items that can be avoided like plastic bags, takeaway coffee cups, straws and plastic bottles