You will learn
- Plan a fair test about light.
- Measure and record shadow data.
- Graph results.
- Evaluate and suggest improvements.
Version 0.2 · expanded edition · built from cited public sources Content is based on the official frameworks and sources listed under Sources and standards. No official endorsement is claimed. Written in the style of common primary school assessments. No exam result is promised.
Student lesson
- Plan, test, record, graph, conclude and evaluate.
- Change one variable only.
- Repeat for reliable results.
- Use numbers in a conclusion.
Words to know
a careful search for answers
a factor that can change
what the evidence shows
to judge how well it went
1. Discover: The shadow challenge
Group E asks, “Does the distance from the torch change shadow height?” They change the toy distance, keep the toy and torch the same and repeat three times. Their graph shows shadow height falls as distance rises. “Our conclusion uses numbers,” says Kojo.
Think: What did they control?
2. Understand: Investigation
Idea 1: Plan
State a testable question, choose the independent variable (distance), the dependent variable (shadow height) and the controlled variables (torch, toy, screen).
Idea 2: Run and record
Measure carefully, repeat three times and record in a table with units. Plot a graph to show the pattern.
Idea 3: Conclude and evaluate
Write a conclusion with numbers, then evaluate: Was it fair? Where could errors come from? What would you change next time?
3. Worked examples
Example 1 (I show you): Plan
Question.
- Testable.
- Name variables.
- List controls.
Answer: A clear question names variables.
Example 2 (We do it together): Record
Three trials.
- Table.
- Units.
- Repeat.
Answer: Record all trials with units.
Example 3 (You try): Conclude
Shadow falls.
Show the steps and answer
- Use numbers.
- Link to question.
- Explain.
Answer: Use numbers and science ideas.
Did you know?
Astronomers use shadows during eclipses to study how the Moon blocks light from the Sun.
Why this matters
A full investigation brings together every science skill you have learned.
4. Explore: Shadow investigation
Plan and carry out an investigation on shadow size and distance.
- Write the question and prediction.
- List variables and method.
- Test and record three trials.
- Graph, conclude and evaluate.
Think about it: what did you notice?
What did you notice? Careful controls gave clear patterns.
5. Practise
Say it in a sentence
Use these starters when you talk about the lesson. Say them out loud.
- An ___ is a careful search for answers.
- A ___ is a factor that can change.
- A ___ uses evidence.
- To ___ is to judge how well it went.
Guided practice
Question 1. What do we change?
Independent variable.
Question 2. What do we measure?
Dependent variable.
Question 3. What do we keep?
Controls.
Independent practice
Level 1: Start
- What do we change?
- What do we measure?
- What do we keep?
- How often repeat?
- What is a conclusion?
Level 2: Grow
- Why fair test?
- Why graph?
- Why evaluate?
Level 3: Stretch
- Plan the test.
- Record results.
- Write conclusion.
Answers are in the answer key below. Try first, then check.
6. Apply: Science in everyday life
Plan an investigation about reflection.
Show a sample answer
Name variables.
Another one. Tell a family member one thing from this lesson. Use the words you learned.
Show a sample answer
A clear sentence that uses at least one word from Words to know.
7. Common mistakes
Fix: Repeat.
Fix: Use data.
8. Lesson summary and revision card
- I can plan a fair test about light.
- I can measure and record shadow data.
- I can graph results.
- I can evaluate and suggest improvements.
9. Check and master
Answer all 14 questions. You will see feedback after each one.
Your result appears here after you answer every question.
10. Key takeaways
- Plan, test, record, graph, conclude and evaluate.
- Change one variable only.
- Repeat for reliable results.
- Use numbers in a conclusion.
11. Next lesson
Next lesson: Sound production. Keep going with the next idea in this course.
Exam practice
These questions are written in the style of common school and international primary assessments. Try them on your own, without looking back. Then check your answers in the marking guide. The marks are shown in brackets.
- Write a testable question and name the variables. [3 marks]
- List two controlled variables. [2 marks]
- Write a conclusion with numbers. [3 marks]
- Suggest one improvement. [2 marks]
Total: 10 marks.
Marking guide and model answers
- Question [1]; independent [1]; dependent [1]
- 1 each
- Pattern [1]; numbers [1]; answers question [1]
- Change [1]; reason [1]
Score guide: 9 to 10 = secure. 6 to 8 = nearly there, revise the parts you missed. Under 6 = work through the lesson again with a grown-up.
Printable worksheet
- What do we change?
- What do we measure?
- What do we keep?
- How often repeat?
- What is a conclusion?
- Why fair test?
- Why graph?
- Why evaluate?
- Plan the test.
- Record results.
Homework
Plan your own light investigation and share it with your family.
Answer key and marking scheme
| Question | Expected response | Marks |
|---|---|---|
| 1. What do we change? | Independent variable. | 1 |
| 2. What do we measure? | Dependent variable. | 1 |
| 3. What do we keep? | Controls. | 1 |
| 4. How often repeat? | Three times. | 1 |
| 5. What is a conclusion? | What evidence shows. | 1 |
| 6. Why fair test? | Find the cause. | 1 |
| 7. Why graph? | See pattern. | 1 |
| 8. Why evaluate? | Improve. | 1 |
| 9. Plan the test. | Plan. | 1 |
| 10. Record results. | Table. | 1 |
| Total | 10 |
Independent practice answers. Level 1: 1 Independent variable.; 2 Dependent variable.; 3 Controls.; 4 Three times.; 5 What evidence shows.. Level 2: 1 Find the cause.; 2 See pattern.; 3 Improve.. Level 3: 1 Plan.; 2 Table.; 3 Paragraph..
Quiz answers: 1 B, 2 C, 3 A, 4 B, 5 C, 6 A, 7 B, 8 C, 9 A, 10 B, 11 C, 12 A, Challenge 1 B, Challenge 2 C.
Mastery and remediation
| Objective | Bronze (Developing) | Silver (Proficient) | Gold (Advanced) |
|---|---|---|---|
| O1 Plan a fair test about light | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
| O2 Measure and record shadow data | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
| O3 Graph results | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
| O4 Evaluate and suggest improvements | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
Courseversity badge thresholds (overall quiz score): Gold = 90–100%; Silver = 80–89.9%; Bronze = 70–79.9%. A badge is never a full record of progress.
If a learner struggles
- Find the misconception: “One trial is enough.” Repeat.
- Explain another way: use real objects, pictures or actions first, then words.
- Show a simpler example: Plan, test and evaluate a light investigation.
- Guided practice: work through one example together and let the learner try the next one.
- Reassess: use the quiz again or the worksheet.
- Move on when the learner shows Silver-level evidence independently.
For parents and guardians
In this lesson your child runs a full light investigation. You do not need to be an expert to help.
- Help plan the test.
- Ask “What stays the same?”
- Use safe torches.
- Ask “how do you know?” after each answer, and listen.
- Praise effort, not only right answers. Mistakes are how we learn.
- Ten to fifteen minutes a day is better than one long session.
Teacher package
1–5. Objectives, prerequisites, materials, preparation, duration
Lesson objectives. Learners will: plan a fair test about light; measure and record shadow data; graph results; evaluate and suggest improvements.
Prerequisite knowledge. Grade 3 physical ideas: forces, materials, and how to measure and record in fair tests.
Materials. Torch, ruler, graph paper. Low-resource options: use chalk or charcoal on a board or wall, drawings in the sand, and objects from the classroom instead of printed materials.
Preparation. Print planning sheets.
Suggested duration. 45–60 minutes. It can be split into two shorter sessions.
6–9. Teaching procedure, explanation notes, guided and independent activities
Introduction (5 min). Ask, “How can we find out how shadows change?”
Explanation (10 min). Teach full investigation.
Guided activity (10 min). Learners plan.
Independent activity (10 min). Learners test and share.
Assessment and reflection (5 min). Ask each learner to say one thing they learned and how they know it.
Key questions. Fair? Reliable? What did we learn?
Teacher explanation notes. Start with real objects and safe, hands-on observation. Then talk about what was seen, then draw and write. Always say “how do you know?”. Keep to the safety notes, and use local, safe materials.
10–12. Differentiation, formative assessment, common misconceptions
Support. Use real objects and pictures, short sentences and a partner. Let learners point, show or draw instead of writing. Extension. Ask learners to find a new example at home and explain how they know.
Formative assessment. Listen to learners read and explain, ask “how do you know?”, and check the independent work.
Misconceptions. “One trial is enough.” Repeat.
13–15. Assessment questions, answer keys, marking scheme
Use the quiz, the 10-mark exam practice and the worksheet on this page. All answers and marking guides are in the answer sections above. Re-check every answer before use.
16–19. Remediation, enrichment, homework, teacher reflection
Remediation. Plan, test and evaluate a light investigation. Enrichment. Look for one new example near your home or school, draw it and explain it to someone. Homework. See above.
Teacher reflection. After teaching, record: which ideas learners understood; which misconceptions occurred; which activities worked; which learners need more practice; and what to improve next time.
Sources and standards
This lesson is based on the sources below, and no official endorsement is claimed. Reference starting points: Next Generation Science Standards, Cambridge Primary Science and the IB Primary Years Programme. Where a standard code is named, it points to the official framework.
Research used to shape this lesson. Courseversity Science curriculum, Grade 4 Unit 4, topic 10; Next Generation Science Standards, waves and their applications (light); Cambridge Primary Science Stage 4, physics: light and dark; IB Primary Years Programme, how the world works. These sources informed the lesson.