How to Perform in PSLE | Learner’s Guide Vol 0115 | English, Mathematics and Science: Keep Given, Derived and Assumed Information Separate

Chapter 1: The job before the answer

A large share of examination error begins when information changes status without the learner noticing. A fact printed in the question is given. A result obtained by a legal calculation or inference is derived. A detail added without support is assumed. The three can sit in one answer, but they cannot be treated as equal. The reliable method is a small ledger: G for given, D for derived and A for assumed. Before a final claim, every important sentence, number or mechanism must earn one of those labels.

This is a control skill, not a memory trick. Surface details can change while the underlying reasoning remains the same. A name can become another name; a percentage can become a different percentage; a battery can become a stretched spring; a narrated claim can become a reported thought. If the learner recognises only the example, transfer is weak. If the learner can name the relationship and rebuild it, transfer becomes possible.

Use four anchors. Source asks where the information, quantity or energy begins. Status asks what kind of thing it is at this moment. Route asks which legal step connects it to the next result. Limit asks how far the conclusion may extend. These anchors slow down the exact point at which a confident but unsupported answer usually appears.

Chapter 2: The decision sequence

• Step 1. Copy only the minimum given facts needed for the question.
• Step 2. Mark calculations, comparisons and text-based inferences as derived.
• Step 3. Put a warning beside any detail supplied from habit, real-world knowledge or guesswork.
• Step 4. State the rule or evidence that turns a given fact into a derived result.
• Step 5. Test whether the answer still works after removing an assumed detail.
• Step 6. Use assumptions only when the question explicitly permits or requires them.
• Step 7. Keep the final claim no stronger than the strongest supported derived step.

During learning, say every step aloud. During the paper, compress the same routine into short marks: a box, an arrow, a base label, an owner tag or the letters G, D and A. Compression is useful only after the full reasoning has become stable. Skipping a step before it is understood creates speed without control.

Do not measure success only by the final answer. A learner may arrive at the correct answer using an unsafe assumption, and that route will fail on the next variation. Check whether the source was identified, the status was preserved, the route was legal and the limit was respected. Those are the transferable parts.

Chapter 3: The errors that look reasonable

The most dangerous distractors are not random. They preserve some correct detail while changing its role. They may attach knowledge to the wrong person, a percentage to the wrong base, an effect to the wrong source or an inference to unsupported information. Diagnosis must therefore name the role error, not merely say the learner was careless.

• Trap 1. Calling a familiar fact given when it is not in the question. Repair it by returning to the source–status–route–limit anchors before adding more information.
• Trap 2. Treating a guess as a reasonable inference without evidence. Repair it by returning to the source–status–route–limit anchors before adding more information.
• Trap 3. Hiding an assumption inside a calculation. Repair it by returning to the source–status–route–limit anchors before adding more information.
• Trap 4. Copying data correctly but deriving from the wrong pair. Repair it by returning to the source–status–route–limit anchors before adding more information.
• Trap 5. Using a scientifically true fact that does not belong to the tested setup. Repair it by returning to the source–status–route–limit anchors before adding more information.
• Trap 6. Treating a character’s claim as passage fact. Repair it by returning to the source–status–route–limit anchors before adding more information.
• Trap 7. Treating a rounded number as exact in later work. Repair it by returning to the source–status–route–limit anchors before adding more information.
• Trap 8. Writing a broad conclusion from one narrow derived result. Repair it by returning to the source–status–route–limit anchors before adding more information.

Build an error log with precise labels. Useful entries include “reader knowledge transferred to character”, “percentage applied to new base instead of original”, “effect named as source”, and “assumption upgraded to given fact”. An exact error label becomes a warning that can be recognised in a different question. The phrase “silly mistake” teaches nothing.

Chapter 4: Worked examples with misconception repair

Worked example 1

Question situation. English: The passage says Nabil left at dawn; his reason is not stated.

Tempting answer. He left early because he was afraid.

Precise repair. Departure time is given; fear is assumed unless another clue supports it.

Mechanism. A plausible story is not automatically a text-based inference. Notice that the repair does not merely replace one sentence with another. It identifies which element changed role and restores the correct direction, base, owner or evidence status.

Transfer move. Change one surface feature while preserving the reasoning job. Replace a name, value, object, material or order of information. Solve again without using the original wording. If the method survives, the learner is beginning to own the job.

Worked example 2

Question situation. Mathematics: A rectangle has area 48 cm² and length 8 cm.

Tempting answer. The width is given as 6 cm.

Precise repair. Area and length are given; width 6 cm is derived by division.

Mechanism. Show the legal operation that changes status. Notice that the repair does not merely replace one sentence with another. It identifies which element changed role and restores the correct direction, base, owner or evidence status.

Transfer move. Change one surface feature while preserving the reasoning job. Replace a name, value, object, material or order of information. Solve again without using the original wording. If the method survives, the learner is beginning to own the job.

Worked example 3

Question situation. Science: A plant in Setup A grew 4 cm more than one in Setup B.

Tempting answer. Fertiliser caused the difference.

Precise repair. The growth difference may be given or derived; causation requires the setups to differ fairly in fertiliser.

Mechanism. Do not hide design assumptions inside the conclusion. Notice that the repair does not merely replace one sentence with another. It identifies which element changed role and restores the correct direction, base, owner or evidence status.

Transfer move. Change one surface feature while preserving the reasoning job. Replace a name, value, object, material or order of information. Solve again without using the original wording. If the method survives, the learner is beginning to own the job.

Worked example 4

Question situation. English: A character says, ‘I posted the parcel.’

Tempting answer. The parcel was definitely posted.

Precise repair. The statement is given as a character’s claim; its truth may remain unverified.

Mechanism. Source ownership affects information status. Notice that the repair does not merely replace one sentence with another. It identifies which element changed role and restores the correct direction, base, owner or evidence status.

Transfer move. Change one surface feature while preserving the reasoning job. Replace a name, value, object, material or order of information. Solve again without using the original wording. If the method survives, the learner is beginning to own the job.

Worked example 5

Question situation. Mathematics: A diagram looks like a square but only opposite sides are labelled equal.

Tempting answer. All four sides are equal.

Precise repair. The appearance is not a given condition; do not assume properties not marked or stated.

Mechanism. Diagrams are evidence only to the degree that labels support them. Notice that the repair does not merely replace one sentence with another. It identifies which element changed role and restores the correct direction, base, owner or evidence status.

Transfer move. Change one surface feature while preserving the reasoning job. Replace a name, value, object, material or order of information. Solve again without using the original wording. If the method survives, the learner is beginning to own the job.

Worked example 6

Question situation. Science: Water droplets appear outside a cold cup.

Tempting answer. Water leaked through the cup.

Precise repair. Droplets are observed; leakage is an assumption unless evidence supports it. Condensation is a derived explanation from relevant knowledge.

Mechanism. Separate observation from mechanism. Notice that the repair does not merely replace one sentence with another. It identifies which element changed role and restores the correct direction, base, owner or evidence status.

Transfer move. Change one surface feature while preserving the reasoning job. Replace a name, value, object, material or order of information. Solve again without using the original wording. If the method survives, the learner is beginning to own the job.

Worked example 7

Question situation. English: The narrator pauses and avoids eye contact.

Tempting answer. The narrator is guilty.

Precise repair. The actions are given; guilt is one possible inference but may be too strong without more evidence.

Mechanism. Derived meaning needs an evidence bridge and calibrated certainty. Notice that the repair does not merely replace one sentence with another. It identifies which element changed role and restores the correct direction, base, owner or evidence status.

Transfer move. Change one surface feature while preserving the reasoning job. Replace a name, value, object, material or order of information. Solve again without using the original wording. If the method survives, the learner is beginning to own the job.

Worked example 8

Question situation. Mathematics: A price is $80 after a 20% discount.

Tempting answer. The original price is $100.

Precise repair. The final price and discount are given; the original is derived because $80 is 80% of it.

Mechanism. Label the base before reversing the percentage. Notice that the repair does not merely replace one sentence with another. It identifies which element changed role and restores the correct direction, base, owner or evidence status.

Transfer move. Change one surface feature while preserving the reasoning job. Replace a name, value, object, material or order of information. Solve again without using the original wording. If the method survives, the learner is beginning to own the job.

Worked example 9

Question situation. Science: Three trials give similar readings.

Tempting answer. The measuring instrument is perfectly accurate.

Precise repair. Consistency is given; reliability may be derived cautiously; perfect accuracy is assumed.

Mechanism. One evidence type cannot establish every quality. Notice that the repair does not merely replace one sentence with another. It identifies which element changed role and restores the correct direction, base, owner or evidence status.

Transfer move. Change one surface feature while preserving the reasoning job. Replace a name, value, object, material or order of information. Solve again without using the original wording. If the method survives, the learner is beginning to own the job.

Worked example 10

Question situation. English: The headline calls a plan ‘bold’.

Tempting answer. The writer admires every part of the plan.

Precise repair. The word choice is given; a favourable tone may be derived locally, but total approval is assumed.

Mechanism. Keep inference scope attached to the evidence. Notice that the repair does not merely replace one sentence with another. It identifies which element changed role and restores the correct direction, base, owner or evidence status.

Transfer move. Change one surface feature while preserving the reasoning job. Replace a name, value, object, material or order of information. Solve again without using the original wording. If the method survives, the learner is beginning to own the job.

Worked example 11

Question situation. Mathematics: The answer 3.7 is rounded to one decimal place.

Tempting answer. The exact value is 3.7.

Precise repair. The rounded result is given; the exact value lies within a range and cannot be recovered uniquely.

Mechanism. Do not upgrade rounded information to exact status. Notice that the repair does not merely replace one sentence with another. It identifies which element changed role and restores the correct direction, base, owner or evidence status.

Transfer move. Change one surface feature while preserving the reasoning job. Replace a name, value, object, material or order of information. Solve again without using the original wording. If the method survives, the learner is beginning to own the job.

Worked example 12

Question situation. Science: A bulb does not light in one circuit.

Tempting answer. The battery is flat.

Precise repair. Non-lighting is observed; a flat battery is only one possible cause among open circuit, faulty bulb or poor contact.

Mechanism. List alternatives before selecting a mechanism. Notice that the repair does not merely replace one sentence with another. It identifies which element changed role and restores the correct direction, base, owner or evidence status.

Transfer move. Change one surface feature while preserving the reasoning job. Replace a name, value, object, material or order of information. Solve again without using the original wording. If the method survives, the learner is beginning to own the job.

Chapter 5: Diagnose the smallest unstable step

When an answer fails, do not restart the whole topic automatically. Find the smallest unstable decision. Did the learner select the wrong fact? Did a statement lose its owner? Did a percentage lose its base? Did the energy chain skip a receiver? Did a derived result absorb an assumption? The correct repair depends on the location of the break.

Use a short interview. Ask, “Where did this information come from?”, “What is it a percentage of?”, “Who could know this?”, “What receives the energy next?”, or “Which line supports that detail?” The learner’s first uncertain pause usually reveals more than the written final answer. Repair that step, then immediately test it in a new context.

Next, test the competing explanation. Write the tempting answer beside the repaired answer. Identify the single word, base or link that separates them. A useful contrast is small enough to remember: knows versus believes; original versus current; source versus effect; given versus assumed. Broad lectures are less effective than a sharp contrast followed by a fresh example.

Chapter 6: Practice progression

Progress from support to independence. Begin by classifying only. Then complete a missing link. Next, repair a wrong answer. After that, produce a full answer without prompts. Finally, transfer the job after a delay. Difficulty should increase by removing support or changing surface form, not by making every feature complicated at once.

• Round A — label the source or owner only.
• Round B — label the information or quantity status.
• Round C — draw the legal route to the next step.
• Round D — state the scope limit.
• Round E — repair a tempting answer in one sentence.
• Round F — explain why the repair is legal.
• Round G — create a new example with the same mechanism.
• Round H — mix this job with a competing job and choose correctly.

Practice variation 1. Begin from this situation: English: The passage says Nabil left at dawn; his reason is not stated. Change one important surface feature. Write the source, status, route and limit. Then write a tempting answer modelled on “He left early because he was afraid.” and repair it using the principle “Departure time is given; fear is assumed unless another clue supports it.”.

Practice variation 2. Begin from this situation: Mathematics: A rectangle has area 48 cm² and length 8 cm. Change one important surface feature. Write the source, status, route and limit. Then write a tempting answer modelled on “The width is given as 6 cm.” and repair it using the principle “Area and length are given; width 6 cm is derived by division.”.

Practice variation 3. Begin from this situation: Science: A plant in Setup A grew 4 cm more than one in Setup B. Change one important surface feature. Write the source, status, route and limit. Then write a tempting answer modelled on “Fertiliser caused the difference.” and repair it using the principle “The growth difference may be given or derived; causation requires the setups to differ fairly in fertiliser.”.

Practice variation 4. Begin from this situation: English: A character says, ‘I posted the parcel.’ Change one important surface feature. Write the source, status, route and limit. Then write a tempting answer modelled on “The parcel was definitely posted.” and repair it using the principle “The statement is given as a character’s claim; its truth may remain unverified.”.

Practice variation 5. Begin from this situation: Mathematics: A diagram looks like a square but only opposite sides are labelled equal. Change one important surface feature. Write the source, status, route and limit. Then write a tempting answer modelled on “All four sides are equal.” and repair it using the principle “The appearance is not a given condition; do not assume properties not marked or stated.”.

Practice variation 6. Begin from this situation: Science: Water droplets appear outside a cold cup. Change one important surface feature. Write the source, status, route and limit. Then write a tempting answer modelled on “Water leaked through the cup.” and repair it using the principle “Droplets are observed; leakage is an assumption unless evidence supports it. Condensation is a derived explanation from relevant knowledge.”.

Practice variation 7. Begin from this situation: English: The narrator pauses and avoids eye contact. Change one important surface feature. Write the source, status, route and limit. Then write a tempting answer modelled on “The narrator is guilty.” and repair it using the principle “The actions are given; guilt is one possible inference but may be too strong without more evidence.”.

Practice variation 8. Begin from this situation: Mathematics: A price is $80 after a 20% discount. Change one important surface feature. Write the source, status, route and limit. Then write a tempting answer modelled on “The original price is $100.” and repair it using the principle “The final price and discount are given; the original is derived because $80 is 80% of it.”.

Chapter 7: Delayed transfer

Immediate success may come from echoing the explanation. Wait forty-eight to seventy-two hours, then attempt four questions: one familiar structure with new details, one case where the tempting answer becomes correct because new evidence is supplied, one case with an irrelevant detail, and one case from another subject. Retrieve the method before reopening this guide.

Mark retrieval separately from accuracy. A learner who reaches the right answer only after a large prompt has not yet achieved independent control. Record the smallest prompt needed. On the next delayed attempt, reduce that prompt. The goal is not zero struggle; the goal is productive struggle that ends with the learner rebuilding the route.

One week later, perform a blank-page check. Write the job in one sentence, list three traps, invent one example and describe the independent check. Compare this retrieval with the guide. Any missing or distorted part becomes the next small practice target. Finish by using the repaired rule on a different question.

Chapter 8: Check by a different route

Repeating the original work with the original assumption often reproduces the same mistake. An independent check changes the route. Reverse the direction of a claim and see whether the passage supports it. Use a multiplier after a line-by-line percentage calculation. Trace energy backwards from the observable effect to its source. Remove all assumed details and see whether the answer remains complete.

• Source check — can I name where each important item begins?
• Status check — is it stated, believed, derived, stored, transferred, observed or assumed?
• Direction check — have cause and effect, original and final, or source and receiver been reversed?
• Evidence check — which exact line, value, comparison or observation supports the step?
• Scope check — did I write always, only or proves when the evidence is narrower?
• Unit and label check — is every number or object still attached to the correct name?
• Completion check — did I answer every requested part and then stop?

Chapter 9: Examination control

Under time pressure, use a compact reset. Stop for a few seconds. Box the requested outcome. Mark the source or owner. Add one status label. Draw the next legal arrow. Then write the shortest complete answer. This prevents the first plausible story, arithmetic shortcut or familiar science phrase from taking over the response.

If two options remain, ask which one preserves all labels. The stronger option keeps the correct person, base, object, unit, time and evidence strength. The weaker option often contains a true statement attached to the wrong target. Reject an answer for that attachment error even when its individual words look familiar.

If the question continues to consume time, mark it and move on. When you return, perform one named check rather than rereading passively. Check the knowledge owner, recalculate from the labelled base, trace the energy receiver, or delete unsupported assumptions. A second attempt needs a new action to become genuinely independent.

Chapter 10: Mixed mini-assessment

Mini-task 1. Mathematics: A diagram looks like a square but only opposite sides are labelled equal. Identify what is secure, what must be derived and what would be unsafe to assume. Explain why “All four sides are equal.” is tempting. Then write a corrected response using this principle: The appearance is not a given condition; do not assume properties not marked or stated.

Mini-task 2. Science: Water droplets appear outside a cold cup. Identify what is secure, what must be derived and what would be unsafe to assume. Explain why “Water leaked through the cup.” is tempting. Then write a corrected response using this principle: Droplets are observed; leakage is an assumption unless evidence supports it. Condensation is a derived explanation from relevant knowledge.

Mini-task 3. English: The narrator pauses and avoids eye contact. Identify what is secure, what must be derived and what would be unsafe to assume. Explain why “The narrator is guilty.” is tempting. Then write a corrected response using this principle: The actions are given; guilt is one possible inference but may be too strong without more evidence.

Mini-task 4. Mathematics: A price is $80 after a 20% discount. Identify what is secure, what must be derived and what would be unsafe to assume. Explain why “The original price is $100.” is tempting. Then write a corrected response using this principle: The final price and discount are given; the original is derived because $80 is 80% of it.

Mini-task 5. Science: Three trials give similar readings. Identify what is secure, what must be derived and what would be unsafe to assume. Explain why “The measuring instrument is perfectly accurate.” is tempting. Then write a corrected response using this principle: Consistency is given; reliability may be derived cautiously; perfect accuracy is assumed.

Mini-task 6. English: The headline calls a plan ‘bold’. Identify what is secure, what must be derived and what would be unsafe to assume. Explain why “The writer admires every part of the plan.” is tempting. Then write a corrected response using this principle: The word choice is given; a favourable tone may be derived locally, but total approval is assumed.

Mini-task 7. Mathematics: The answer 3.7 is rounded to one decimal place. Identify what is secure, what must be derived and what would be unsafe to assume. Explain why “The exact value is 3.7.” is tempting. Then write a corrected response using this principle: The rounded result is given; the exact value lies within a range and cannot be recovered uniquely.

Mini-task 8. Science: A bulb does not light in one circuit. Identify what is secure, what must be derived and what would be unsafe to assume. Explain why “The battery is flat.” is tempting. Then write a corrected response using this principle: Non-lighting is observed; a flat battery is only one possible cause among open circuit, faulty bulb or poor contact.

Score each mini-task on four marks: correct source, correct status, legal reasoning route and controlled conclusion. Sentence polish matters, but it cannot rescue a missing reasoning link. First make the answer defensible; then make it concise.

Chapter 11: A twenty-minute practice routine

Spend three minutes retrieving the method without notes. Spend six minutes on two supported cases. Spend six minutes on two mixed cases without prompts. Spend three minutes checking by a different route. Spend two minutes recording one exact error and the repair rule. This routine is short enough to repeat and specific enough to show progress.

Do not repeat the same worksheet until the layout becomes familiar. Change wording, order, numbers, speakers, objects or materials. Keep the reasoning job stable for two examples, then place a competing job beside it. Choosing the method is part of performance. A learner who can execute only after someone names the method is not yet ready for independent transfer.

Retire a practice set when the learner can explain the route, reject the distractor and succeed after a delay. More identical questions may add fatigue without adding control. Move to mixed retrieval, then return later. Spacing exposes whether the method is available when the visible reminder has disappeared.

Chapter 12: Guidance for parents and tutors

Ask short diagnostic questions instead of supplying the whole correction. “Who owns that statement?”, “One hundred per cent of what?”, “Where does the energy enter?”, and “Which part did you assume?” are useful because each question points to one control point. Let the learner repair the answer aloud before writing it again.

Praise a visible reasoning move: preserving a character’s knowledge boundary, labelling the percentage base, tracing an energy receiver or removing an assumption. Precise praise helps the learner recognise what to repeat. If a content gap appears, route the learner to the relevant subject hub rather than forcing this performance guide to become a substitute textbook.

Keep records small. Note the date, the job, whether a prompt was needed, the exact error label and the delayed result. This is enough to see whether learning is becoming independent. Large piles of marked work can hide the same recurring break. A short evidence trail makes the next teaching decision clearer.

Chapter 13: Frequently asked questions

What counts as given?

Information explicitly stated, labelled or unambiguously shown in the question.

What counts as derived?

A result supported by a valid operation, comparison, rule or text-based inference.

Are all assumptions wrong?

No, but they must be authorised, necessary and stated when relevant.

Can background knowledge create a derived result?

Yes when the subject requires that knowledge and it is correctly applied to the given conditions.

How do I spot a hidden assumption?

Ask which exact line, label, calculation or rule supports each new detail.

What if a diagram looks obvious?

Use only properties that are stated, marked or necessarily follow from valid geometry.

How does the ledger help under time pressure?

G, D and A labels expose unsupported leaps before they enter the final answer.

What is the final check?

Remove every A item and see whether the answer remains complete and defensible.

Chapter 14: Next route

Continue through the permanent PSLE Learning Guide. For deeper teaching, use the eduKateSG Learning Hubs, which remains the canonical owner for wider subject coverage.

Continue this four-volume batch through Vol 0112, Vol 0113, Vol 0114. Each guide trains a different job while reinforcing careful source, status, route and scope control.

Completion is demonstrated, not declared. Meet a new question, identify the correct source or owner, preserve the status of the information, take a legal reasoning step and stop before an assumption expands the conclusion. If one step is unstable, practise that step alone, return after a delay and test it in a changed context.

Extension: explain, reverse and rebuild

Extension 1. Use this situation: English: The passage says Nabil left at dawn; his reason is not stated. Explain the exact role error in “He left early because he was afraid.”. Rebuild the answer using “Departure time is given; fear is assumed unless another clue supports it.”. Then invent one extra fact that would make the tempting answer more defensible, and state how that new fact changes the source, status, route or limit of the reasoning. This final step prevents memorising a prohibition without understanding its conditions.

Extension 2. Use this situation: Mathematics: A rectangle has area 48 cm² and length 8 cm. Explain the exact role error in “The width is given as 6 cm.”. Rebuild the answer using “Area and length are given; width 6 cm is derived by division.”. Then invent one extra fact that would make the tempting answer more defensible, and state how that new fact changes the source, status, route or limit of the reasoning. This final step prevents memorising a prohibition without understanding its conditions.

Extension 3. Use this situation: Science: A plant in Setup A grew 4 cm more than one in Setup B. Explain the exact role error in “Fertiliser caused the difference.”. Rebuild the answer using “The growth difference may be given or derived; causation requires the setups to differ fairly in fertiliser.”. Then invent one extra fact that would make the tempting answer more defensible, and state how that new fact changes the source, status, route or limit of the reasoning. This final step prevents memorising a prohibition without understanding its conditions.

Extension 4. Use this situation: English: A character says, ‘I posted the parcel.’ Explain the exact role error in “The parcel was definitely posted.”. Rebuild the answer using “The statement is given as a character’s claim; its truth may remain unverified.”. Then invent one extra fact that would make the tempting answer more defensible, and state how that new fact changes the source, status, route or limit of the reasoning. This final step prevents memorising a prohibition without understanding its conditions.

Extension 5. Use this situation: Mathematics: A diagram looks like a square but only opposite sides are labelled equal. Explain the exact role error in “All four sides are equal.”. Rebuild the answer using “The appearance is not a given condition; do not assume properties not marked or stated.”. Then invent one extra fact that would make the tempting answer more defensible, and state how that new fact changes the source, status, route or limit of the reasoning. This final step prevents memorising a prohibition without understanding its conditions.

Extension 6. Use this situation: Science: Water droplets appear outside a cold cup. Explain the exact role error in “Water leaked through the cup.”. Rebuild the answer using “Droplets are observed; leakage is an assumption unless evidence supports it. Condensation is a derived explanation from relevant knowledge.”. Then invent one extra fact that would make the tempting answer more defensible, and state how that new fact changes the source, status, route or limit of the reasoning. This final step prevents memorising a prohibition without understanding its conditions.

Extension 7. Use this situation: English: The narrator pauses and avoids eye contact. Explain the exact role error in “The narrator is guilty.”. Rebuild the answer using “The actions are given; guilt is one possible inference but may be too strong without more evidence.”. Then invent one extra fact that would make the tempting answer more defensible, and state how that new fact changes the source, status, route or limit of the reasoning. This final step prevents memorising a prohibition without understanding its conditions.

Extension 8. Use this situation: Mathematics: A price is $80 after a 20% discount. Explain the exact role error in “The original price is $100.”. Rebuild the answer using “The final price and discount are given; the original is derived because $80 is 80% of it.”. Then invent one extra fact that would make the tempting answer more defensible, and state how that new fact changes the source, status, route or limit of the reasoning. This final step prevents memorising a prohibition without understanding its conditions.

Extension 9. Use this situation: Science: Three trials give similar readings. Explain the exact role error in “The measuring instrument is perfectly accurate.”. Rebuild the answer using “Consistency is given; reliability may be derived cautiously; perfect accuracy is assumed.”. Then invent one extra fact that would make the tempting answer more defensible, and state how that new fact changes the source, status, route or limit of the reasoning. This final step prevents memorising a prohibition without understanding its conditions.

Extension 10. Use this situation: English: The headline calls a plan ‘bold’. Explain the exact role error in “The writer admires every part of the plan.”. Rebuild the answer using “The word choice is given; a favourable tone may be derived locally, but total approval is assumed.”. Then invent one extra fact that would make the tempting answer more defensible, and state how that new fact changes the source, status, route or limit of the reasoning. This final step prevents memorising a prohibition without understanding its conditions.

Extension 11. Use this situation: Mathematics: The answer 3.7 is rounded to one decimal place. Explain the exact role error in “The exact value is 3.7.”. Rebuild the answer using “The rounded result is given; the exact value lies within a range and cannot be recovered uniquely.”. Then invent one extra fact that would make the tempting answer more defensible, and state how that new fact changes the source, status, route or limit of the reasoning. This final step prevents memorising a prohibition without understanding its conditions.

Extension 12. Use this situation: Science: A bulb does not light in one circuit. Explain the exact role error in “The battery is flat.”. Rebuild the answer using “Non-lighting is observed; a flat battery is only one possible cause among open circuit, faulty bulb or poor contact.”. Then invent one extra fact that would make the tempting answer more defensible, and state how that new fact changes the source, status, route or limit of the reasoning. This final step prevents memorising a prohibition without understanding its conditions.