Opening

BUILD · SCIENCE · Lesson 9 of 10

Can this test answer its question?

Learning intention

Plan and use a fair test of how card height affects shadow height.

Question: do taller cards make taller shadows?

A team changed height and distance.

Help repair its plan.

Success looks like

Identify the intended change, measurement and controls.
Repair a plan that changes two factors.
Use repeated readings to make a supported conclusion.

Retrieval

BUILD · SCIENCE · Lesson 9 of 10

Recall our shadow studio

1. What blocks the light?

2. Can moving a card change shadow size?

3. What unit measures our shadow height?

I do

BUILD · SCIENCE · Lesson 9 of 10

I spot two changed factors

A uses a 2 cm-high card.

B uses a 4 cm-high card.

Their distances are different too.

Two changes muddle the answer

Diagram description

Two tests use cards with different heights. One card is 30 cm and the other 20 cm from the source, so both height and distance change.

I do

BUILD · SCIENCE · Lesson 9 of 10

I repair the comparison

Change card height only.

Keep source and screen still.

Keep card position at 30 cm.

One change at a time

Diagram description

Two tests use cards with different heights. Both cards are placed 30 cm from the source, with a fixed screen 60 cm from the source.

I do

BUILD · SCIENCE · Lesson 9 of 10

I measure and repeat consistently

Measure bottom to top in centimetres.

Use the same edge rule each time.

Keep all readings.

Measure one height in centimetres

Diagram description

Front-view screen with a rectangular shadow beside a ruler. The shadow runs from zero to eight centimetres; use the same top-to-bottom measure each time.

Continue within this stage’s shared time.

We do

BUILD · SCIENCE · Lesson 9 of 10

Make a test contract

Go to interactive investigation

Choose the one change.

Choose what to measure.

Name two controls.

Constructed teaching evidence
Plan part	Choose from these
Change	Card height / source-screen distance
Measure	Shadow height / card colour
Keep same	Card position / card height

W1. Which choices answer our height question?

My response — say it, sketch on paper or type

Repair the fair test

Review the fictional plan, predict the useful repair, then inspect the evidence. Keep honest readings.

Decision 1 of 3

The team changes card height and card-source distance. Can it isolate height alone?

Choose, test, then explain together. Evidence diagrams appear only after your test. Diagram transitions explain the model; they do not represent real elapsed time. Use Pause model to stop transitions and model controls, or your device’s reduced-motion setting. The printed We do activity provides the paper route.

We do

BUILD · SCIENCE · Lesson 9 of 10

What should we do with 9?

Three readings include one difference.

Keep the evidence.

Check and repeat if useful.

Constructed teaching readings, not class observations
Card height	Repeat 1	Repeat 2	Repeat 3
2 cm	4 cm	4 cm	4 cm
4 cm	8 cm	8 cm	9 cm
6 cm	12 cm	12 cm	12 cm

W2. Can we keep a useful conclusion and keep the 9?

My response — say it, sketch on paper or type

Hinge

BUILD · SCIENCE · Lesson 9 of 10

Which plan is fair for this question?

Question: how does card height affect shadow height?

You do

BUILD · SCIENCE · Lesson 9 of 10

Choose your investigation route

Choose the test controls.

Write a method and conclusion.

Review the strength of a claim.

My response — say it, sketch on paper or type

You do

BUILD · SCIENCE · Lesson 9 of 10

Use the evidence

Read or point to one clue.

Record what it supports.

Keep your explanation short.

My response — say it, sketch on paper or type

Continue within this stage’s shared time.

You do

BUILD · SCIENCE · Lesson 9 of 10

Make your own science record

Complete your chosen route.

Use a diagram, words or speech.

Check one answer with the evidence.

My response — say it, sketch on paper or type

You do

BUILD · SCIENCE · Lesson 9 of 10

Check and improve

Does my answer match the evidence?

Have I explained why?

Improve one label or sentence.

My response — say it, sketch on paper or type

Continue within this stage’s shared time.

Review

BUILD · SCIENCE · Lesson 9 of 10

Lundy loop: improve our account

Choose how to share one idea.

Listen to another explanation.

Use evidence to improve our account.

What makes our conclusion stronger?

My response — say it, sketch on paper or type

Exit

BUILD · SCIENCE · Lesson 9 of 10

Three quick checks

E1. What factor did this test change?

E2. Name one thing kept the same.

E3. Should we delete a different reading just to fit the pattern?

My response — say it, sketch on paper or type

My science task sheets

Choose one route with your teacher. Shared evidence and the exit sheet appear in every route. Your work stays here while the page is open; save it before closing.

Evidence: plans and repeated readings

Constructed teaching cases and readings. Source and screen are 60 cm apart.

A • Flawed comparison

2 cm card: 30 cm from source. 4 cm card: 20 cm from source.

B • Repaired comparison

Each card: 30 cm from source. Change height only; keep material, width and orientation the same.

Card height	Reading 1	Reading 2	Reading 3
2 cm	4 cm	4 cm	4 cm
4 cm	8 cm	8 cm	9 cm
6 cm	12 cm	12 cm	12 cm

W1. Name the change, measurement and one control.W2. What should the team do with the 9 cm reading?

Route 1 • Build a fair-test plan

Word bank: card height / shadow height / same / repeat.

S1. What are we deliberately changing? Card height Source-screen distance

S2. What are we measuring? Shadow height Card colour

S3. Keep each card __ cm from the source.S4. Do taller cards give taller or shorter shadows in the table?S5. What should we do if a reading differs?

Route 2 • Record a method and conclusion

Use the repaired plan and readings. Optional practical: use a separate record clearly labelled “our measurements”.

T1. Write the investigation question.

Task	Plan part	Your decision
T2	Change
T2	Measure
T2	Keep same: two things

T3. Write a short method including a repeat.T4. Write a conclusion using two values from the table.T5. Explain what to do with the 9 cm reading.

Route 3 • Review the quality of evidence

A team claims: “Our test proves every shadow is exactly twice the card height.”

X1. Use the readings to identify a problem with “exactly”.X2. Explain why the claim cannot cover every possible setup.X3. Write a more careful conclusion for this setup.X4. Suggest one method check and one extra reading that would improve confidence.

Exit and reflection

Point, draw, write or tell an adult.

E1. What factor did this test change?E2. Name one thing kept the same.E3. Should we delete a different reading just to fit the pattern?R1. Which idea did you improve after hearing evidence?R2. What would you investigate or ask next?