All lessons › Where does the water go? › Lesson 1
Australian primary science · Year 4 · Lesson 1 of 4
The puddle mystery
Inquiry question: Where does a puddle go when it dries up?
Check practical materials
Observing over time
What students learn
Liquid water evaporates into water vapour, a gas we can’t see. Warmth speeds up evaporation.
Success criteria
- I can measure water level over time.
- I can say evaporation is water turning into a gas.
- I can explain why a warm place dries faster.
Preparation and materials
Before this lesson: Students know water can be a liquid or ice.
- Clear plastic cups — 26 (2 per pair)
- Water and marker pens — 13
- Rulers — 13
Teacher setup
- Choose a warm sunny spot and a cool shady spot.
- Keep both cups indoors or under cover so rain can’t refill them.
Safety and adaptations
- Wipe up spills so no one slips.
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.
- Fill two cups to the same level and mark the line.
- Put one in a warm spot and one in a cool spot.
- Predict which will lose water faster.
- Measure and mark each day.
Teacher modelling prompt
Mark the water line on a cup: “Day 1: water is at 80 mm. I draw a line.” Show a photo of a cup after 3 days: “The line is higher than the water. Where did it go?”
Record and explain evidence
Recording question: Does water evaporate faster somewhere warm?
| Day | Warm cup level (mm) | Cool cup level (mm) |
|---|---|---|
| ________________ | ________________ | ________________ |
Example recording headings; record actual observations, including inconclusive results.
Discussion prompt
Which claim is scientific, and why?
Check understanding
What should pupils know? What is evaporation?
Explain with evidence: Use your results to say where water evaporated faster.
Apply the idea: Why do wet clothes dry faster on a sunny, windy day?
Teacher answer guidance and saved classroom work are available through the main lesson experience where supported.