You will learn
- Tell clean from dirty water.
- Explain why clean water matters.
- Describe safe ways to clean water.
- Observe filtering with an adult.
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
- Clean water is safe to drink.
- Dirty water can carry germs.
- Filtering removes solids.
- Boiling or treating water kills germs.
Words to know
free from dirt and germs
not clean
to pass through to remove solids
tiny living things that can make us ill
1. Discover: The brown stream
After heavy rain, the stream near the school turns brown. Fiifi’s teacher says, “Do not drink from it. It can carry germs.” Back in class, she shows how a cloth and sand filter can make muddy water clearer. “But it is still not safe to drink,” she adds.
Think: Why is clear water not always safe?
2. Understand: Clean water
Idea 1: Clean and dirty
Water can look clear but still hold germs. Dirty water has mud, rubbish or germs and can make us ill.
Idea 2: Filtering
A filter removes solids such as mud and leaves. It does not remove all germs.
Idea 3: Making water safe
Water is made safe at treatment plants. At home an adult can boil water to kill germs, or use treated tablets or a safe filter.
3. Worked examples
Example 1 (I show you): Safe?
A brown stream.
- Muddy.
- May hold germs.
- Not safe.
Answer: Muddy stream water is not safe.
Example 2 (We do it together): Filter
Cloth and sand.
- Removes mud.
- Clearer.
- Not germ-free.
Answer: Filters remove solids.
Example 3 (You try): Make safe
Boiled water.
Show the steps and answer
- An adult boils it.
- Kills germs.
- Cooled for drinking.
Answer: Boiling kills germs.
Did you know?
Millions of people have fallen ill from drinking unsafe water; clean water saves lives.
Why this matters
Clean water protects our health.
4. Explore: Water filter model
Filter muddy water with an adult using cloth, sand and gravel.
- Make muddy water in a cup.
- Pour through a bottle filter with cloth, sand, gravel.
- Collect the water.
- Compare clarity.
Think about it: what did you notice?
What did you notice? Water was clearer but not safe to drink.
5. Practise
Say it in a sentence
Use these starters when you talk about the lesson. Say them out loud.
- Dirty water can carry ___.
- A ___ removes mud.
- Boiling kills ___.
- Clear water may still hold ___.
Guided practice
Question 1. What is clean water?
Safe to drink.
Question 2. What are germs?
Tiny living things.
Question 3. What does a filter do?
Removes solids.
Independent practice
Level 1: Start
- What is clean water?
- What are germs?
- What does a filter do?
- What kills germs?
- Can clear water be unsafe?
Level 2: Grow
- Why not drink stream water?
- Why filter?
- Who boils water?
Level 3: Stretch
- Make a filter diagram.
- Explain why clean water matters.
- Make a poster.
Answers are in the answer key below. Try first, then check.
6. Apply: Science in everyday life
How does your family make water safe?
Show a sample answer
Boil or treat.
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: May hold germs.
Fix: Not always.
8. Lesson summary and revision card
- I can tell clean from dirty water.
- I can explain why clean water matters.
- I can describe safe ways to clean water.
- I can observe filtering with an adult.
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
- Clean water is safe to drink.
- Dirty water can carry germs.
- Filtering removes solids.
- Boiling or treating water kills germs.
11. Next lesson
Next lesson: Water conservation. 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.
- What is clean water? [1 mark]
- What does a filter do? [2 marks]
- How can water be made safe? [2 marks]
- Why can clear water be unsafe? [1 mark]
- Safety rule? [2 marks]
Total: 8 marks.
Marking guide and model answers
- Safe to drink [1]
- Removes solids [1]; not germs [1]
- Boil [1]; treat [1]
- Germs [1]
- Never drink test water [1]; adult boils [1]
Score guide: 7 to 8 = secure. 5 to 6 = nearly there, revise the parts you missed. Under 5 = work through the lesson again with a grown-up.
Printable worksheet
- What is clean water?
- What are germs?
- What does a filter do?
- What kills germs?
- Can clear water be unsafe?
- Why not drink stream water?
- Why filter?
- Who boils water?
- Make a filter diagram.
- Explain why clean water matters.
Homework
Draw how your family makes water safe to drink. Add labels.
Answer key and marking scheme
| Question | Expected response | Marks |
|---|---|---|
| 1. What is clean water? | Safe to drink. | 1 |
| 2. What are germs? | Tiny living things. | 1 |
| 3. What does a filter do? | Removes solids. | 1 |
| 4. What kills germs? | Boiling. | 1 |
| 5. Can clear water be unsafe? | Yes. | 1 |
| 6. Why not drink stream water? | Germs. | 1 |
| 7. Why filter? | Remove mud. | 1 |
| 8. Who boils water? | An adult. | 1 |
| 9. Make a filter diagram. | Labelled. | 1 |
| 10. Explain why clean water matters. | Health. | 1 |
| Total | 10 |
Independent practice answers. Level 1: 1 Safe to drink.; 2 Tiny living things.; 3 Removes solids.; 4 Boiling.; 5 Yes.. Level 2: 1 Germs.; 2 Remove mud.; 3 An adult.. Level 3: 1 Labelled.; 2 Health.; 3 Five rules..
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 Tell clean from dirty water | 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 Explain why clean water matters | 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 Describe safe ways to clean water | 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 Observe filtering with an adult | 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: “Clear water is always safe.” May hold germs.
- Explain another way: use real objects, pictures or actions first, then words.
- Show a simpler example: Explain how to make water safe and why.
- 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 learns about clean water and safe filtering. You do not need to be an expert to help.
- Talk about safe water at home.
- Ask, “How is it made safe?”
- Make a filter poster.
- 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: tell clean from dirty water; explain why clean water matters; describe safe ways to clean water; observe filtering with an adult.
Prerequisite knowledge. Grade 1 ideas: weather and the sky, water around us and keeping our environment clean.
Materials. Bottles, cloth, sand, gravel and muddy water (not for drinking). 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. Cut bottle tops. Prepare materials. Label “Not for drinking”.
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 muddy and clear water and ask, “Which is safe?”
Explanation (10 min). Teach clean water.
Guided activity (10 min). Learners filter safely.
Independent activity (10 min). Learners compare.
Assessment and reflection (5 min). Ask each learner to say one thing they learned and how they know it.
Key questions. Is it safe? How do you know?
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. “Clear water is always safe.” May hold germs.
13–15. Assessment questions, answer keys, marking scheme
Use the quiz, the 8-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. Explain how to make water safe and why. 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 2 Unit 7, topic 9; Next Generation Science Standards, structure and properties of matter and Earth systems (2-ESS2 water on Earth); Cambridge Primary Science Stage 2, materials and Earth; IB Primary Years Programme, how the world works. These sources informed the lesson.