You will learn
- Define refraction.
- Explain the bent straw.
- Predict bending direction.
- Relate to lenses.
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
- Light changes speed in different media.
- It bends toward the normal in denser media.
- Refraction makes things look shifted.
- Lenses focus light.
Words to know
the bending of light as it changes speed
the material light travels through
a curved piece of glass or plastic that bends light
bending light rays toward each other
1. Discover: The bent straw
Fatima puts a straw in a glass of water and it looks broken at the surface. “Light from the straw bends as it leaves the water,” says Mr Peprah. “Your brain traces the rays back in straight lines, so the straw seems shifted.”
Think: Why does a swimming pool look shallower than it is?
2. Understand: Refraction
Idea 1: Bending
Refraction is the bending of light when it moves from one medium to another, such as air to water, because its speed changes. In a denser medium light slows down and bends toward the normal.
Idea 2: Everyday
A straw looks bent, a coin looks raised in water and a pool looks shallower because of refraction.
Idea 3: Lenses
A lens refracts light. A convex (converging) lens brings rays together to a focus and is used in magnifying glasses, cameras and spectacles. Refraction splitting white light makes rainbows.
3. Worked examples
Example 1 (I show you): Explain
Bent straw.
- Light bends.
- Water to air.
- Brain traces straight.
Answer: Refraction.
Example 2 (We do it together): Predict
Direction.
- Air to water.
- Toward normal.
- Slower.
Answer: Bends toward normal.
Example 3 (You try): Name
Uses.
Show the steps and answer
- Lens.
- Camera.
- Glasses.
Answer: Several uses.
Did you know?
Light travels about 25 percent slower in water than in air, which is why it bends.
Why this matters
Refraction is behind lenses, spectacles, cameras and microscopes.
4. Explore: Coin trick
Place a coin in an opaque cup, move back until it is just hidden by the rim, then add water slowly and watch the coin reappear.
- Place the coin.
- Move to hide it.
- Pour water slowly.
- Observe.
Think about it: what did you notice?
What did you notice? The coin appeared as light bent at the surface.
5. Practise
Say it in a sentence
Use these starters when you talk about the lesson. Say them out loud.
- ___ is the bending of light as it changes speed.
- A ___ is the material light travels through.
- A ___ is a curved piece of glass that bends light.
- ___ means bending rays toward each other.
Guided practice
Question 1. What is refraction?
Bending.
Question 2. Why does it happen?
Speed change.
Question 3. What is a lens?
Curved glass.
Independent practice
Level 1: Start
- What is refraction?
- Why does it happen?
- What is a lens?
- Name a use.
- Which bends toward normal?
Level 2: Grow
- Why bent straw?
- Why pool shallow?
- Why rainbows?
Level 3: Stretch
- Do the trick.
- Draw rays.
- Explain.
Answers are in the answer key below. Try first, then check.
6. Apply: Science in everyday life
Explain why a straw in water looks bent.
Show a sample answer
Use refraction.
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: Different.
Fix: Speed change.
8. Lesson summary and revision card
- I can define refraction.
- I can explain the bent straw.
- I can predict bending direction.
- I can relate to lenses.
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
- Light changes speed in different media.
- It bends toward the normal in denser media.
- Refraction makes things look shifted.
- Lenses focus light.
11. Next lesson
Next lesson: Sound vibrations. 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 refraction and lens. [2 marks]
- Explain the coin trick. [3 marks]
- Explain why a pool looks shallower. [3 marks]
- Safety rule. [2 marks]
Total: 10 marks.
Marking guide and model answers
- 1 each
- Light bends [1]; leaves water [1]; coin visible [1]
- Refraction [1]; rays traced back straight [1]; appears raised [1]
- 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 refraction?
- Why does it happen?
- What is a lens?
- Name a use.
- Which bends toward normal?
- Why bent straw?
- Why pool shallow?
- Why rainbows?
- Do the trick.
- Draw rays.
Homework
Observe a pencil in a glass of water and draw it.
Answer key and marking scheme
| Question | Expected response | Marks |
|---|---|---|
| 1. What is refraction? | Bending. | 1 |
| 2. Why does it happen? | Speed change. | 1 |
| 3. What is a lens? | Curved glass. | 1 |
| 4. Name a use. | Glasses. | 1 |
| 5. Which bends toward normal? | Denser medium. | 1 |
| 6. Why bent straw? | Refraction. | 1 |
| 7. Why pool shallow? | Refraction. | 1 |
| 8. Why rainbows? | Refraction. | 1 |
| 9. Do the trick. | Notes. | 1 |
| 10. Draw rays. | Diagram. | 1 |
| Total | 10 |
Independent practice answers. Level 1: 1 Bending.; 2 Speed change.; 3 Curved glass.; 4 Glasses.; 5 Denser medium.. Level 2: 1 Refraction.; 2 Refraction.; 3 Refraction.. Level 3: 1 Notes.; 2 Diagram.; 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 Define refraction | 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 the bent straw | 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 Predict bending direction | 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 Relate to lenses | 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: “Refraction and reflection are the same.” Different.
- Explain another way: use real objects, pictures or actions first, then words.
- Show a simpler example: Explain refraction.
- 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 observes refraction safely. You do not need to be an expert to help.
- Try the straw trick.
- Ask “Why bent?”
- Never look at the Sun with lenses.
- 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: define refraction; explain the bent straw; predict bending direction; relate to lenses.
Prerequisite knowledge. Grade 5 ideas: energy forms, light, shadows, sound and heat.
Materials. Plastic cups, coins, water, straws. 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. Fill cups.
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). Put a pencil in water and ask, “Is it broken?”
Explanation (10 min). Teach refraction.
Guided activity (10 min). Learners test.
Independent activity (10 min). Learners explain.
Assessment and reflection (5 min). Ask each learner to say one thing they learned and how they know it.
Key questions. Which way does the light bend? Why?
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. “Refraction and reflection are the same.” Different.
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. Explain refraction. 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 6 Unit 8, topic 7; Next Generation Science Standards, energy and waves; Cambridge Lower Secondary Science, physics; IB Primary Years Programme, how the world works. These sources informed the lesson.