All lessons › Where does the water go? › Lesson 3
Australian primary science · Year 4 · Lesson 3 of 4
Water cycle in a bag
Inquiry question: How does water get from the ocean to the clouds and back?
Check practical materials
Modelling
What students learn
The water cycle: water evaporates, condenses into clouds, falls as precipitation, and collects in oceans, rivers and the ground.
Success criteria
- I can name the stages of the water cycle.
- I can match each part of the model to the real world.
- I can say one way the model is different from real life.
Preparation and materials
Before this lesson: Students can describe evaporation and condensation (lessons 1–2).
- Zip-lock bags — 13
- Water with blue food colouring — 13 × 1/4 cup
- Permanent markers — 13
- Tape — 13
Teacher setup
- Choose a sunny window.
Safety and adaptations
- Seal bags well.
Review your school policies and curriculum requirements before teaching.
How to investigate
The lesson sequence should leave pupils with evidence to interpret, not only an activity to finish.
- Draw the sun, clouds and ocean on the bag.
- Pour in coloured water and seal.
- Tape to a sunny window.
- Observe after 30 minutes and later: record droplets and ‘rain’.
- Label each stage on your drawing.
Teacher modelling prompt
Draw the cycle on the board with arrows, labelling each stage, then show the bag: “The water at the bottom is the ocean. The sun will warm it. Watch for droplets near the top: our clouds.”
Record and explain evidence
Recording question: Which water cycle stages can we see in our bag?
| Stage | What we saw in the bag | Where it happens in real life |
|---|---|---|
| ________________ | ________________ | ________________ |
Example recording headings; record actual observations, including inconclusive results.
Discussion prompt
Which matches what we learned about condensation?
Check understanding
What should pupils know? Put these in order: precipitation, evaporation, collection, condensation.
Explain with evidence: Which part of the bag model is like a cloud? Why?
Apply the idea: Where does rainwater go after it lands on a school oval?
Teacher answer guidance and saved classroom work are available through the main lesson experience where supported.