All lessons › Challenge: Think like a scientist › Lesson 1
Australian primary science · Years 5–6 (challenge) · Lesson 1 of 3
Hypothesis hunters: the shadow rule
Inquiry question: Is there a rule that predicts how big a shadow will be?
Marked no materials needed
Pattern seeking
What students learn
A hypothesis is a testable idea with a reason. Collecting data across a range lets us find a relationship (a rule), and a good rule lets us predict results we haven’t tested yet.
Success criteria
- I can write a hypothesis using ‘If…, then…, because…’.
- I can find a rule linking distance and shadow size.
- I can use my rule to predict an untested result, then check it.
Preparation and materials
Before this lesson: Students know shadows form because light travels in straight lines and is blocked (Light and shadows).
- iPads with Bottlebrush Education open (nothing else needed) — 13 (one per pair)
- Projector or big screen — 1
Teacher setup
- Open Forces & energy › Lab › Shadow maker on your screen to demonstrate.
- Check the iPads are charged and set to Your year › Years 5–6.
Safety and adaptations
Follow school science and equipment risk assessment procedures for the materials used.
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.
- Write a hypothesis using If…, then…, because….
- In Shadow maker, measure the shadow at 10, 20, 30 and 40 cm with cardboard. Record the results.
- Look for the rule. Try: distance × shadow size. What do you notice?
- Use your rule to predict the shadow at 25 cm and at 50 cm (where the screen is).
- Check: 25 cm is not in the app, so explain whether your prediction makes sense. Then try baking paper and clear plastic, and describe how the shadow changes.
Teacher modelling prompt
Open Shadow maker on the big screen and tap a prediction (it unlocks Measure and record). Think aloud: “My hypothesis: if the puppet moves closer to the torch, then the shadow will get bigger, because it blocks more of the spreading light. At 20 cm the shadow is 25 cm. At 10 cm, half the distance, it’s 50 cm: double. I wonder if that’s always true. Let me check 40 cm: if the rule works, it should be about half of 25.”
Record and explain evidence
Recording question: Is there a rule that predicts how big a shadow will be?
| Distance from torch (cm) | Shadow height (cm) | Distance × shadow height | Does it fit the rule? |
|---|---|---|---|
| ________________ | ________________ | ________________ | ________________ |
Example recording headings; record actual observations, including inconclusive results.
Discussion prompt
How do scientists use predictions that turn out wrong?
Check understanding
What should pupils know? What is the difference between a prediction and a hypothesis?
Explain with evidence: Use your rule to predict the shadow at 25 cm. Show how you worked it out.
Apply the idea: A puppet show needs a shadow 100 cm tall. How close to the torch should the puppet be? Explain using the rule.
Teacher answer guidance and saved classroom work are available through the main lesson experience where supported.