PSLE Learner’s Guide · Volume 0815
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An object is generally more stable when it has a wider supporting base and a lower centre of gravity, because it can tilt farther before its weight acts beyond the base.
Series routes: Use the complete PSLE Learner’s Guide volume directory, the original PSLE Learning Guide and the Science learning hub.
This guide uses original Primary 6 practice and does not predict a live question. Consult the SEAB PSLE formats examined in 2026 page for official information.
Open the full chapter index
- 1. Define stability by resistance to toppling
- 2. Identify the supporting base
- 3. Locate the centre of gravity
- 4. Explain the toppling threshold
- 5. Compare one factor fairly
- 6. Separate total mass from mass distribution
- 7. Apply the mechanism to design
- 8. Control examination claims
- 9. Worked examples
- 10. Independent practice
- 11. Delayed transfer
- 12. Family guidance and FAQs
CHAPTER 1 OF 12 · Back to contents
1. Define stability by resistance to toppling
A stable object returns to or remains in its supported position after a small disturbance. Stability is not the same as strength, mass alone or being permanently impossible to overturn.
Build the explanation by naming supporting base and centre of gravity and line of action of weight. A remembered keyword is not enough: connect the observation to the mechanism and identify what would have to change for the conclusion to change.
Repair the nearest misconception by checking controlled comparison of one factor and returning to tilting threshold rather than absolute safety. State why the tempting alternative is too strong, incomplete or about a different stage.
- Check supporting base and centre of gravity.
- Check line of action of weight.
- Check controlled comparison of one factor.
- Check tilting threshold rather than absolute safety.
CHAPTER 2 OF 12 · Back to contents
2. Identify the supporting base
The supporting base is the area enclosed by the points or surfaces touching the support. A wider base provides a larger region within which the downward line of action of weight can remain while the object tilts.
Build the explanation by naming supporting base and centre of gravity and line of action of weight. A remembered keyword is not enough: connect the observation to the mechanism and identify what would have to change for the conclusion to change.
Repair the nearest misconception by checking controlled comparison of one factor and returning to tilting threshold rather than absolute safety. State why the tempting alternative is too strong, incomplete or about a different stage.
CHAPTER 3 OF 12 · Back to contents
3. Locate the centre of gravity
The centre of gravity is the point through which the object’s weight may be treated as acting. Lowering this point usually requires a greater tilt before its line of action passes outside the supporting base.
Build the explanation by naming supporting base and centre of gravity and line of action of weight. A remembered keyword is not enough: connect the observation to the mechanism and identify what would have to change for the conclusion to change.
Repair the nearest misconception by checking controlled comparison of one factor and returning to tilting threshold rather than absolute safety. State why the tempting alternative is too strong, incomplete or about a different stage.
CHAPTER 4 OF 12 · Back to contents
4. Explain the toppling threshold
While the line of action of weight falls within the base, the object can remain supported. Once that line passes beyond the edge, the turning effect favours continued rotation and the object topples.
Build the explanation by naming supporting base and centre of gravity and line of action of weight. A remembered keyword is not enough: connect the observation to the mechanism and identify what would have to change for the conclusion to change.
Repair the nearest misconception by checking controlled comparison of one factor and returning to tilting threshold rather than absolute safety. State why the tempting alternative is too strong, incomplete or about a different stage.
CHAPTER 5 OF 12 · Back to contents
5. Compare one factor fairly
To test base width, keep mass distribution, height, material, surface and disturbance consistent. To test centre-of-gravity height, keep the base and external conditions consistent.
Build the explanation by naming supporting base and centre of gravity and line of action of weight. A remembered keyword is not enough: connect the observation to the mechanism and identify what would have to change for the conclusion to change.
Repair the nearest misconception by checking controlled comparison of one factor and returning to tilting threshold rather than absolute safety. State why the tempting alternative is too strong, incomplete or about a different stage.
CHAPTER 6 OF 12 · Back to contents
6. Separate total mass from mass distribution
A heavier object is not automatically more stable. Where its mass is placed affects the centre of gravity; a smaller low-mounted mass can improve stability more than an equal mass placed high.
Build the explanation by naming supporting base and centre of gravity and line of action of weight. A remembered keyword is not enough: connect the observation to the mechanism and identify what would have to change for the conclusion to change.
Repair the nearest misconception by checking controlled comparison of one factor and returning to tilting threshold rather than absolute safety. State why the tempting alternative is too strong, incomplete or about a different stage.
CHAPTER 7 OF 12 · Back to contents
7. Apply the mechanism to design
Broad feet, low heavy components and careful load placement can improve stability in stands, vehicles and containers. The explanation must name the changed feature and how it delays the toppling condition.
Build the explanation by naming supporting base and centre of gravity and line of action of weight. A remembered keyword is not enough: connect the observation to the mechanism and identify what would have to change for the conclusion to change.
Repair the nearest misconception by checking controlled comparison of one factor and returning to tilting threshold rather than absolute safety. State why the tempting alternative is too strong, incomplete or about a different stage.
CHAPTER 8 OF 12 · Back to contents
8. Control examination claims
Use generally or under the same conditions, name the wider base or lower centre of gravity, and link it to a larger tilt needed before the line of action leaves the base. Do not promise that the object cannot topple.
Build the explanation by naming supporting base and centre of gravity and line of action of weight. A remembered keyword is not enough: connect the observation to the mechanism and identify what would have to change for the conclusion to change.
Repair the nearest misconception by checking controlled comparison of one factor and returning to tilting threshold rather than absolute safety. State why the tempting alternative is too strong, incomplete or about a different stage.
CHAPTER 9 OF 12 · Back to contents
9. Worked examples
Worked case 1: Two identical blocks stand on different faces. Which is more stable?
Controlled answer. The block resting on the wider face. Its supporting base is larger under the same mass distribution.
Mechanism. Identify the exact relationship, apply the relevant rule and preserve every stated condition. A surface clue may be compatible with several explanations, so the answer must show what makes this case decisive.
Misconception repair. Do not turn partial evidence into complete proof. Name the closest wrong answer, identify its missing condition and explain why the observed evidence supports the narrower conclusion.
Transfer. Explain using the line of action of weight. Solve the altered case from the mechanism rather than copying the previous wording.
Reverse construction. Begin with the controlled answer “The block resting on the wider face” and invent a fresh prompt that would justify it for the same reason. Then change one decisive condition to create a near-nonexample. This reverse task checks whether the learner owns the boundary rather than merely recognising the original sentence.
Explanation standard. A complete explanation names the observation, connects it to the rule and limits the conclusion to what follows. It should remain valid if decorative details are removed. If the explanation depends on the story topic instead of the decisive relation, rebuild it.
Audit. Recheck supporting base and centre of gravity, line of action of weight, controlled comparison of one factor, tilting threshold rather than absolute safety. Decide whether the evidence proves the conclusion or only supports a limited statement.
Worked case 2: Where should a heavy battery be placed in a toy vehicle for stability?
Controlled answer. Low in the vehicle. A low heavy component lowers the centre of gravity.
Mechanism. Identify the exact relationship, apply the relevant rule and preserve every stated condition. A surface clue may be compatible with several explanations, so the answer must show what makes this case decisive.
Misconception repair. Do not turn partial evidence into complete proof. Name the closest wrong answer, identify its missing condition and explain why the observed evidence supports the narrower conclusion.
Transfer. Keep the wheel spacing unchanged. Solve the altered case from the mechanism rather than copying the previous wording.
Reverse construction. Begin with the controlled answer “Low in the vehicle” and invent a fresh prompt that would justify it for the same reason. Then change one decisive condition to create a near-nonexample. This reverse task checks whether the learner owns the boundary rather than merely recognising the original sentence.
Explanation standard. A complete explanation names the observation, connects it to the rule and limits the conclusion to what follows. It should remain valid if decorative details are removed. If the explanation depends on the story topic instead of the decisive relation, rebuild it.
Audit. Recheck supporting base and centre of gravity, line of action of weight, controlled comparison of one factor, tilting threshold rather than absolute safety. Decide whether the evidence proves the conclusion or only supports a limited statement.
Worked case 3: Repair: a heavy object can never topple.
Controlled answer. Mass alone does not prevent toppling. Base width, centre of gravity and disturbance also matter.
Mechanism. Identify the exact relationship, apply the relevant rule and preserve every stated condition. A surface clue may be compatible with several explanations, so the answer must show what makes this case decisive.
Misconception repair. Do not turn partial evidence into complete proof. Name the closest wrong answer, identify its missing condition and explain why the observed evidence supports the narrower conclusion.
Transfer. Give a tall heavy counterexample. Solve the altered case from the mechanism rather than copying the previous wording.
Reverse construction. Begin with the controlled answer “Mass alone does not prevent toppling” and invent a fresh prompt that would justify it for the same reason. Then change one decisive condition to create a near-nonexample. This reverse task checks whether the learner owns the boundary rather than merely recognising the original sentence.
Explanation standard. A complete explanation names the observation, connects it to the rule and limits the conclusion to what follows. It should remain valid if decorative details are removed. If the explanation depends on the story topic instead of the decisive relation, rebuild it.
Audit. Recheck supporting base and centre of gravity, line of action of weight, controlled comparison of one factor, tilting threshold rather than absolute safety. Decide whether the evidence proves the conclusion or only supports a limited statement.
Worked case 4: Repair: a wide base guarantees perfect safety.
Controlled answer. A wide base generally improves stability but sufficiently large forces or slopes can still topple the object. Stability is conditional, not absolute.
Mechanism. Identify the exact relationship, apply the relevant rule and preserve every stated condition. A surface clue may be compatible with several explanations, so the answer must show what makes this case decisive.
Misconception repair. Do not turn partial evidence into complete proof. Name the closest wrong answer, identify its missing condition and explain why the observed evidence supports the narrower conclusion.
Transfer. Name one changed condition. Solve the altered case from the mechanism rather than copying the previous wording.
Reverse construction. Begin with the controlled answer “A wide base generally improves stability but sufficiently large forces or slopes can still topple the object” and invent a fresh prompt that would justify it for the same reason. Then change one decisive condition to create a near-nonexample. This reverse task checks whether the learner owns the boundary rather than merely recognising the original sentence.
Explanation standard. A complete explanation names the observation, connects it to the rule and limits the conclusion to what follows. It should remain valid if decorative details are removed. If the explanation depends on the story topic instead of the decisive relation, rebuild it.
Audit. Recheck supporting base and centre of gravity, line of action of weight, controlled comparison of one factor, tilting threshold rather than absolute safety. Decide whether the evidence proves the conclusion or only supports a limited statement.
Worked case 5: What happens when the line of action of weight passes outside the base?
Controlled answer. The object tends to topple. The weight then produces a turning effect beyond the support edge.
Mechanism. Identify the exact relationship, apply the relevant rule and preserve every stated condition. A surface clue may be compatible with several explanations, so the answer must show what makes this case decisive.
Misconception repair. Do not turn partial evidence into complete proof. Name the closest wrong answer, identify its missing condition and explain why the observed evidence supports the narrower conclusion.
Transfer. Sketch the support edge. Solve the altered case from the mechanism rather than copying the previous wording.
Reverse construction. Begin with the controlled answer “The object tends to topple” and invent a fresh prompt that would justify it for the same reason. Then change one decisive condition to create a near-nonexample. This reverse task checks whether the learner owns the boundary rather than merely recognising the original sentence.
Explanation standard. A complete explanation names the observation, connects it to the rule and limits the conclusion to what follows. It should remain valid if decorative details are removed. If the explanation depends on the story topic instead of the decisive relation, rebuild it.
Audit. Recheck supporting base and centre of gravity, line of action of weight, controlled comparison of one factor, tilting threshold rather than absolute safety. Decide whether the evidence proves the conclusion or only supports a limited statement.
Worked case 6: Why does a lower centre of gravity help?
Controlled answer. A greater tilt is usually needed before the weight’s line of action leaves the base. The threshold is reached later.
Mechanism. Identify the exact relationship, apply the relevant rule and preserve every stated condition. A surface clue may be compatible with several explanations, so the answer must show what makes this case decisive.
Misconception repair. Do not turn partial evidence into complete proof. Name the closest wrong answer, identify its missing condition and explain why the observed evidence supports the narrower conclusion.
Transfer. Compare two otherwise identical objects. Solve the altered case from the mechanism rather than copying the previous wording.
Reverse construction. Begin with the controlled answer “A greater tilt is usually needed before the weight’s line of action leaves the base” and invent a fresh prompt that would justify it for the same reason. Then change one decisive condition to create a near-nonexample. This reverse task checks whether the learner owns the boundary rather than merely recognising the original sentence.
Explanation standard. A complete explanation names the observation, connects it to the rule and limits the conclusion to what follows. It should remain valid if decorative details are removed. If the explanation depends on the story topic instead of the decisive relation, rebuild it.
Audit. Recheck supporting base and centre of gravity, line of action of weight, controlled comparison of one factor, tilting threshold rather than absolute safety. Decide whether the evidence proves the conclusion or only supports a limited statement.
Worked case 7: Why does a wider base help?
Controlled answer. It gives a wider supporting region for the line of action. The object can tilt farther before the line crosses an edge.
Mechanism. Identify the exact relationship, apply the relevant rule and preserve every stated condition. A surface clue may be compatible with several explanations, so the answer must show what makes this case decisive.
Misconception repair. Do not turn partial evidence into complete proof. Name the closest wrong answer, identify its missing condition and explain why the observed evidence supports the narrower conclusion.
Transfer. Keep height and mass distribution constant. Solve the altered case from the mechanism rather than copying the previous wording.
Reverse construction. Begin with the controlled answer “It gives a wider supporting region for the line of action” and invent a fresh prompt that would justify it for the same reason. Then change one decisive condition to create a near-nonexample. This reverse task checks whether the learner owns the boundary rather than merely recognising the original sentence.
Explanation standard. A complete explanation names the observation, connects it to the rule and limits the conclusion to what follows. It should remain valid if decorative details are removed. If the explanation depends on the story topic instead of the decisive relation, rebuild it.
Audit. Recheck supporting base and centre of gravity, line of action of weight, controlled comparison of one factor, tilting threshold rather than absolute safety. Decide whether the evidence proves the conclusion or only supports a limited statement.
Worked case 8: Can shape affect stability without changing total mass?
Controlled answer. Yes. Shape can change the base or distribution of mass.
Mechanism. Identify the exact relationship, apply the relevant rule and preserve every stated condition. A surface clue may be compatible with several explanations, so the answer must show what makes this case decisive.
Misconception repair. Do not turn partial evidence into complete proof. Name the closest wrong answer, identify its missing condition and explain why the observed evidence supports the narrower conclusion.
Transfer. Describe one redesign. Solve the altered case from the mechanism rather than copying the previous wording.
Reverse construction. Begin with the controlled answer “Yes” and invent a fresh prompt that would justify it for the same reason. Then change one decisive condition to create a near-nonexample. This reverse task checks whether the learner owns the boundary rather than merely recognising the original sentence.
Explanation standard. A complete explanation names the observation, connects it to the rule and limits the conclusion to what follows. It should remain valid if decorative details are removed. If the explanation depends on the story topic instead of the decisive relation, rebuild it.
Audit. Recheck supporting base and centre of gravity, line of action of weight, controlled comparison of one factor, tilting threshold rather than absolute safety. Decide whether the evidence proves the conclusion or only supports a limited statement.
Worked case 9: Which is a fair test of base width?
Controlled answer. Use objects identical except for the supporting base width. Other variables must not explain the result.
Mechanism. Identify the exact relationship, apply the relevant rule and preserve every stated condition. A surface clue may be compatible with several explanations, so the answer must show what makes this case decisive.
Misconception repair. Do not turn partial evidence into complete proof. Name the closest wrong answer, identify its missing condition and explain why the observed evidence supports the narrower conclusion.
Transfer. State how the push will be kept consistent. Solve the altered case from the mechanism rather than copying the previous wording.
Reverse construction. Begin with the controlled answer “Use objects identical except for the supporting base width” and invent a fresh prompt that would justify it for the same reason. Then change one decisive condition to create a near-nonexample. This reverse task checks whether the learner owns the boundary rather than merely recognising the original sentence.
Explanation standard. A complete explanation names the observation, connects it to the rule and limits the conclusion to what follows. It should remain valid if decorative details are removed. If the explanation depends on the story topic instead of the decisive relation, rebuild it.
Audit. Recheck supporting base and centre of gravity, line of action of weight, controlled comparison of one factor, tilting threshold rather than absolute safety. Decide whether the evidence proves the conclusion or only supports a limited statement.
Worked case 10: Which is a fair test of centre-of-gravity height?
Controlled answer. Keep the base and object shape controlled while changing mass placement vertically. This isolates the height of mass distribution.
Mechanism. Identify the exact relationship, apply the relevant rule and preserve every stated condition. A surface clue may be compatible with several explanations, so the answer must show what makes this case decisive.
Misconception repair. Do not turn partial evidence into complete proof. Name the closest wrong answer, identify its missing condition and explain why the observed evidence supports the narrower conclusion.
Transfer. Measure the same tilting condition. Solve the altered case from the mechanism rather than copying the previous wording.
Reverse construction. Begin with the controlled answer “Keep the base and object shape controlled while changing mass placement vertically” and invent a fresh prompt that would justify it for the same reason. Then change one decisive condition to create a near-nonexample. This reverse task checks whether the learner owns the boundary rather than merely recognising the original sentence.
Explanation standard. A complete explanation names the observation, connects it to the rule and limits the conclusion to what follows. It should remain valid if decorative details are removed. If the explanation depends on the story topic instead of the decisive relation, rebuild it.
Audit. Recheck supporting base and centre of gravity, line of action of weight, controlled comparison of one factor, tilting threshold rather than absolute safety. Decide whether the evidence proves the conclusion or only supports a limited statement.
Worked case 11: Should the push be larger for one object in a comparison?
Controlled answer. No. Different disturbances would confound the test.
Mechanism. Identify the exact relationship, apply the relevant rule and preserve every stated condition. A surface clue may be compatible with several explanations, so the answer must show what makes this case decisive.
Misconception repair. Do not turn partial evidence into complete proof. Name the closest wrong answer, identify its missing condition and explain why the observed evidence supports the narrower conclusion.
Transfer. Use a controlled ramp angle or repeated push method. Solve the altered case from the mechanism rather than copying the previous wording.
Reverse construction. Begin with the controlled answer “No” and invent a fresh prompt that would justify it for the same reason. Then change one decisive condition to create a near-nonexample. This reverse task checks whether the learner owns the boundary rather than merely recognising the original sentence.
Explanation standard. A complete explanation names the observation, connects it to the rule and limits the conclusion to what follows. It should remain valid if decorative details are removed. If the explanation depends on the story topic instead of the decisive relation, rebuild it.
Audit. Recheck supporting base and centre of gravity, line of action of weight, controlled comparison of one factor, tilting threshold rather than absolute safety. Decide whether the evidence proves the conclusion or only supports a limited statement.
Worked case 12: Does a low centre of gravity mean the object cannot move?
Controlled answer. No. It concerns resistance to toppling, not all translation or motion.
Mechanism. Identify the exact relationship, apply the relevant rule and preserve every stated condition. A surface clue may be compatible with several explanations, so the answer must show what makes this case decisive.
Misconception repair. Do not turn partial evidence into complete proof. Name the closest wrong answer, identify its missing condition and explain why the observed evidence supports the narrower conclusion.
Transfer. Separate sliding from toppling. Solve the altered case from the mechanism rather than copying the previous wording.
Reverse construction. Begin with the controlled answer “No” and invent a fresh prompt that would justify it for the same reason. Then change one decisive condition to create a near-nonexample. This reverse task checks whether the learner owns the boundary rather than merely recognising the original sentence.
Explanation standard. A complete explanation names the observation, connects it to the rule and limits the conclusion to what follows. It should remain valid if decorative details are removed. If the explanation depends on the story topic instead of the decisive relation, rebuild it.
Audit. Recheck supporting base and centre of gravity, line of action of weight, controlled comparison of one factor, tilting threshold rather than absolute safety. Decide whether the evidence proves the conclusion or only supports a limited statement.
CHAPTER 10 OF 12 · Back to contents
10. Independent practice
Practice 1: A container is top-heavy. What does that imply?
Explained answer. Much of its mass is high, raising the centre of gravity. It may topple more easily under similar conditions.
Delayed transfer. Move the load lower. Cover the answer later and rebuild the chain.
Control question. Which exact condition does the nearest wrong answer miss? State it before checking.
Extension. Change one decisive feature while keeping the story similar. Explain why the conclusion now stays or changes.
Independent proof. Restate the answer without copying its wording. Your version must identify the evidence, the governing relationship and the boundary of the claim. Then write one fact that would be relevant but still insufficient on its own. This separates explanation from repetition.
Delayed comparison. Save this item beside the near-nonexample you created. On the next attempt, compare them before answering and point to the single feature that controls the difference. If more than one feature changed, revise the pair so the comparison stays fair.
Practice 2: Why are racing vehicles often designed low?
Explained answer. A lower centre of gravity can improve resistance to toppling during turns. The explanation concerns mass distribution and turning effects.
Delayed transfer. Do not claim shape removes all accident risk. Cover the answer later and rebuild the chain.
Control question. Which exact condition does the nearest wrong answer miss? State it before checking.
Extension. Change one decisive feature while keeping the story similar. Explain why the conclusion now stays or changes.
Independent proof. Restate the answer without copying its wording. Your version must identify the evidence, the governing relationship and the boundary of the claim. Then write one fact that would be relevant but still insufficient on its own. This separates explanation from repetition.
Delayed comparison. Save this item beside the near-nonexample you created. On the next attempt, compare them before answering and point to the single feature that controls the difference. If more than one feature changed, revise the pair so the comparison stays fair.
Practice 3: A stool gains outward-spreading legs. What feature changes?
Explained answer. Its supporting base becomes wider. The contact points enclose a larger support area.
Delayed transfer. Keep leg strength separate from stability. Cover the answer later and rebuild the chain.
Control question. Which exact condition does the nearest wrong answer miss? State it before checking.
Extension. Change one decisive feature while keeping the story similar. Explain why the conclusion now stays or changes.
Independent proof. Restate the answer without copying its wording. Your version must identify the evidence, the governing relationship and the boundary of the claim. Then write one fact that would be relevant but still insufficient on its own. This separates explanation from repetition.
Delayed comparison. Save this item beside the near-nonexample you created. On the next attempt, compare them before answering and point to the single feature that controls the difference. If more than one feature changed, revise the pair so the comparison stays fair.
Practice 4: Can an object slide before it topples?
Explained answer. Yes. Friction and the applied force determine sliding as well as stability.
Delayed transfer. Do not infer toppling from motion alone. Cover the answer later and rebuild the chain.
Control question. Which exact condition does the nearest wrong answer miss? State it before checking.
Extension. Change one decisive feature while keeping the story similar. Explain why the conclusion now stays or changes.
Independent proof. Restate the answer without copying its wording. Your version must identify the evidence, the governing relationship and the boundary of the claim. Then write one fact that would be relevant but still insufficient on its own. This separates explanation from repetition.
Delayed comparison. Save this item beside the near-nonexample you created. On the next attempt, compare them before answering and point to the single feature that controls the difference. If more than one feature changed, revise the pair so the comparison stays fair.
Practice 5: Why use generally in the conclusion?
Explained answer. Other conditions such as surface slope, friction and disturbance can change the outcome. The rule compares controlled cases.
Delayed transfer. State the controlled conditions. Cover the answer later and rebuild the chain.
Control question. Which exact condition does the nearest wrong answer miss? State it before checking.
Extension. Change one decisive feature while keeping the story similar. Explain why the conclusion now stays or changes.
Independent proof. Restate the answer without copying its wording. Your version must identify the evidence, the governing relationship and the boundary of the claim. Then write one fact that would be relevant but still insufficient on its own. This separates explanation from repetition.
Delayed comparison. Save this item beside the near-nonexample you created. On the next attempt, compare them before answering and point to the single feature that controls the difference. If more than one feature changed, revise the pair so the comparison stays fair.
Practice 6: What observation could measure stability in a ramp test?
Explained answer. The angle at which toppling begins. A larger critical angle indicates greater resistance under the setup.
Delayed transfer. Repeat trials and keep orientation fixed. Cover the answer later and rebuild the chain.
Control question. Which exact condition does the nearest wrong answer miss? State it before checking.
Extension. Change one decisive feature while keeping the story similar. Explain why the conclusion now stays or changes.
Independent proof. Restate the answer without copying its wording. Your version must identify the evidence, the governing relationship and the boundary of the claim. Then write one fact that would be relevant but still insufficient on its own. This separates explanation from repetition.
Delayed comparison. Save this item beside the near-nonexample you created. On the next attempt, compare them before answering and point to the single feature that controls the difference. If more than one feature changed, revise the pair so the comparison stays fair.
Practice 7: What is the closest wrong explanation?
Explained answer. That greater mass alone always causes greater stability. It ignores base geometry and mass distribution.
Delayed transfer. Repair it with a controlled comparison. Cover the answer later and rebuild the chain.
Control question. Which exact condition does the nearest wrong answer miss? State it before checking.
Extension. Change one decisive feature while keeping the story similar. Explain why the conclusion now stays or changes.
Independent proof. Restate the answer without copying its wording. Your version must identify the evidence, the governing relationship and the boundary of the claim. Then write one fact that would be relevant but still insufficient on its own. This separates explanation from repetition.
Delayed comparison. Save this item beside the near-nonexample you created. On the next attempt, compare them before answering and point to the single feature that controls the difference. If more than one feature changed, revise the pair so the comparison stays fair.
Practice 8: State the full method.
Explained answer. Identify the supporting base and centre of gravity, compare one feature fairly, and explain toppling by whether the weight’s line of action remains within the base. Treat stability as a threshold under stated conditions, not a guarantee.
Delayed transfer. Apply the method to one household object. Cover the answer later and rebuild the chain.
Control question. Which exact condition does the nearest wrong answer miss? State it before checking.
Extension. Change one decisive feature while keeping the story similar. Explain why the conclusion now stays or changes.
Independent proof. Restate the answer without copying its wording. Your version must identify the evidence, the governing relationship and the boundary of the claim. Then write one fact that would be relevant but still insufficient on its own. This separates explanation from repetition.
Delayed comparison. Save this item beside the near-nonexample you created. On the next attempt, compare them before answering and point to the single feature that controls the difference. If more than one feature changed, revise the pair so the comparison stays fair.
CHAPTER 11 OF 12 · Back to contents
11. Delayed transfer
On day one, solve clear examples. On day three, mix examples, near-nonexamples and incomplete evidence. On day seven, solve without headings or a word bank. Delay reveals whether the method can be reconstructed independently.
Keep an error log for the first failed stage: reading, representation, rule, execution or checking. The earliest failure identifies the repair.
Interleave this skill with neighbouring ideas that share vocabulary. Classify each item only after naming the distinguishing condition.
In timed work, mark the relationship, apply the rule, write the conclusion and audit one condition. If checking changes the answer, record the overlooked feature.
Create a teach-back card with a near-nonexample on the front and the repaired mechanism on the back. Explain why the tempting answer fails.
Finish with one basic example, one boundary case and one transfer case. Supply explanations that a classmate can verify.
For a second delayed test, reverse the direction: start from a conclusion and invent evidence that would justify it, then evidence that would be insufficient. This exposes the boundary between relevance and proof.
CHAPTER 12 OF 12 · Back to contents
12. Family guidance and FAQs
Guidance for parents and tutors
Ask for the decisive condition before confirming the answer. Use prompts such as “What exactly happened?”, “Which stage or meaning is this?” and “What would prove it?”
Fade support from labelled examples to mixed questions and delayed open response. Independent retrieval after time and topic change is the target.
Praise precise claim control. Narrowing an answer when evidence is incomplete is scientific and academic strength.
Frequently asked questions
Should I memorise the rule?
Memorise the compact rule, then practise examples and near-nonexamples so the conditions remain visible.
What if two answers seem possible?
Return to the exact relationship and choose the option satisfying every stated condition without adding facts.
Why delay practice?
Immediate repetition may depend on the recent explanation; delay tests reconstruction.
How should an error be corrected?
Name the first failed stage and practise it with a changed example.
When is the skill ready?
When the learner can explain, apply and transfer it after a delay.
What is the final audit?
Check relationship, mechanism, claim strength and whole-question fit.
Next routes
Continue at the Science learning hub or return to the series directory.