You will learn
- State a claim.
- Cite evidence.
- Give reasoning.
- Use scientific words.
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
- A claim answers the question.
- Evidence supports the claim.
- Reasoning links them with science.
- Explanations use correct vocabulary.
Words to know
a statement of what you found
data that supports the claim
the science that links evidence to the claim
a statement of why something happens
1. Discover: The melting ice
Naana writes: “Ice in the sun melted faster than ice in shade. The sun ice melted in 12 minutes and the shade ice in 25 minutes. Heat from the Sun gives particles energy, so ice melts faster when it is warmer.” Her teacher says, “Claim, evidence, reasoning. Well done.”
Think: Which sentence is the evidence?
2. Understand: Explanations
Idea 1: CER
A good explanation has three parts: a claim (the answer), evidence (data) and reasoning (the science that connects them).
Idea 2: Vocabulary
Use exact science words such as particles, energy, friction or evaporate instead of vague words like stuff.
Idea 3: Check
Does the evidence really support the claim? Does the reasoning use correct science? Is the explanation clear enough for a friend?
3. Worked examples
Example 1 (I show you): Find
Claim.
- The answer.
- Starts it.
- Short.
Answer: The claim answers the question.
Example 2 (We do it together): Find
Evidence.
- Numbers.
- Times.
- Data.
Answer: 12 and 25 minutes.
Example 3 (You try): Find
Reasoning.
Show the steps and answer
- Science.
- Why.
- Particles.
Answer: Heat gives particles energy.
Did you know?
The scientific method of claim, evidence and reasoning is used in courtrooms, hospitals and laboratories.
Why this matters
Explanations let others check our thinking and learn from it.
4. Explore: Write CER
Take one set of results and write a claim, evidence and reasoning paragraph, then swap and check a partner’s.
- Read the results.
- Write the claim.
- Add evidence.
- Add reasoning and swap.
Think about it: what did you notice?
What did you notice? Clear evidence made claims stronger.
5. Practise
Say it in a sentence
Use these starters when you talk about the lesson. Say them out loud.
- A ___ is a statement of what you found.
- ___ is data that supports it.
- ___ links them with science.
- An ___ says why.
Guided practice
Question 1. What is a claim?
The answer.
Question 2. What is evidence?
Data.
Question 3. What is reasoning?
Science link.
Independent practice
Level 1: Start
- What is a claim?
- What is evidence?
- What is reasoning?
- Name a science word.
- Why explain?
Level 2: Grow
- Why evidence?
- Why reasoning?
- Why exact words?
Level 3: Stretch
- Write CER.
- Swap and check.
- Improve.
Answers are in the answer key below. Try first, then check.
6. Apply: Science in everyday life
Write a CER about plants and light.
Show a sample answer
Use three parts.
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: It does.
Fix: Use exact ones.
8. Lesson summary and revision card
- I can state a claim.
- I can cite evidence.
- I can give reasoning.
- I can use scientific words.
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
- A claim answers the question.
- Evidence supports the claim.
- Reasoning links them with science.
- Explanations use correct vocabulary.
11. Next lesson
Next lesson: Investigation evaluation. 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.
- Define claim, evidence and reasoning. [3 marks]
- Write a short CER paragraph. [4 marks]
- Check a partner’s CER. [1 mark]
- Safety rule. [2 marks]
Total: 10 marks.
Marking guide and model answers
- 1 each
- Claim [1]; evidence [1]; reasoning [1]; science words [1]
- One helpful comment
- Any [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 is a claim?
- What is evidence?
- What is reasoning?
- Name a science word.
- Why explain?
- Why evidence?
- Why reasoning?
- Why exact words?
- Write CER.
- Swap and check.
Homework
Write a CER about why a puddle dried.
Answer key and marking scheme
| Question | Expected response | Marks |
|---|---|---|
| 1. What is a claim? | The answer. | 1 |
| 2. What is evidence? | Data. | 1 |
| 3. What is reasoning? | Science link. | 1 |
| 4. Name a science word. | Particles. | 1 |
| 5. Why explain? | Share. | 1 |
| 6. Why evidence? | Support. | 1 |
| 7. Why reasoning? | Link. | 1 |
| 8. Why exact words? | Clear. | 1 |
| 9. Write CER. | Paragraph. | 1 |
| 10. Swap and check. | Notes. | 1 |
| Total | 10 |
Independent practice answers. Level 1: 1 The answer.; 2 Data.; 3 Science link.; 4 Particles.; 5 Share.. Level 2: 1 Support.; 2 Link.; 3 Clear.. Level 3: 1 Paragraph.; 2 Notes.; 3 Sentence..
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 State a claim | 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 Cite evidence | 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 Give reasoning | 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 Use scientific words | 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: “A claim needs no evidence.” It does.
- Explain another way: use real objects, pictures or actions first, then words.
- Show a simpler example: Write scientific explanations.
- 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 writes explanations. You do not need to be an expert to help.
- Ask “Why did it happen?”
- Ask for proof.
- Praise reasons.
- 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: state a claim; cite evidence; give reasoning; use scientific words.
Prerequisite knowledge. Grade 4 inquiry ideas: asking questions, fair testing, measuring, recording results in tables and drawing conclusions.
Materials. Results sheet, pencil. 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 results.
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). Show a result and ask, “Why did this happen?”
Explanation (10 min). Teach CER.
Guided activity (10 min). Learners write.
Independent activity (10 min). Learners swap.
Assessment and reflection (5 min). Ask each learner to say one thing they learned and how they know it.
Key questions. Claim? Evidence? Reasoning?
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. “A claim needs no evidence.” It does.
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. Write scientific explanations. 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 5 Unit 1, topic 9; Next Generation Science Standards, science and engineering practices; Cambridge Primary Science Stage 5, thinking and working scientifically; IB Primary Years Programme, how we express ourselves and how the world works. These sources informed the lesson.