PSLE Learner’s Guide · Vol 0350 · Ratio units, whole allocation and integer checks
Find the exact decision this guide helps you make
This guide helps a Primary 6 learner divide a known whole among two or more parts in a stated ratio by counting total ratio units, finding the value of one unit and rebuilding every required part. The short rule is add ratio units, divide the whole by the total units, then multiply and rebuild the whole. You will learn the mechanism, see worked examples, repair common misconceptions, practise in stages and use a compact examination routine.
Choose a reading route
- Understand why the error happens
- Use the step-by-step method
- Study eight worked cases
- Build practice and delayed transfer
- Use the examination-control routine
- Guidance for parents and tutors
- Read the FAQs and choose the next route
This is an examination-performance guide, not a replacement for full topic teaching. Use the complete PSLE Learner’s Guide volume directory to move across this series, the PSLE Learning Guide for the wider sequence and the Mathematics Learning Hub for deeper subject instruction.
For complete teaching, worked practice and topic progression beyond this performance decision, continue through the Mathematics Learning Hub. This volume keeps a narrower job: it helps the learner recognise, execute and check one examination decision without competing with the wider topic owner. For a nearby performance routine that is already published, continue to Vol 0346 on aligning ratio-table columns.
A careful note about the current examination year
This article is written for the 2026 PSLE preparation context. SEAB’s official 2026 formats page lists English Language as subject 0001, revised Mathematics as 0008 and revised Science as 0009. Format details can change, so confirm any paper-specific timing, component or administrative instruction with the current official SEAB 2026 source and your school. The reasoning routine taught here is deliberately broader: it strengthens how you read evidence, make a decision and check an answer.
Why this mistake happens
A ratio such as 2:3 does not say there are five objects. It says the whole is represented by five equal ratio units, with two assigned to one named part and three to another. Learners often divide the whole by one ratio number, subtract the two numbers, or attach the larger ratio value to the larger-looking quantity without preserving labels. The reliable method separates ratio units from actual quantities and checks that the allocated parts add back to the original whole.
The mind likes a fast label. A familiar word, operation, result or rule triggers an answer before the conditions have been checked. That shortcut sometimes works in easy practice, so it becomes a habit. In a demanding question, however, a nearby distractor preserves the surface pattern while changing one important condition. The learner then performs a correct-looking move on the wrong object. The repair is to slow only the decision point: identify what is being linked or measured, preserve its labels, test the conditions, and then continue at normal speed.
Think of the method as a chain with four locks. Object: what exact idea or quantity is under discussion? Relationship: how are the relevant parts connected? Condition: what must be true for the move to be valid? Claim: what is the strongest conclusion the evidence actually supports? A weak answer often skips from object to claim. A strong answer makes the two middle locks visible.
The one-line operating rule
Add ratio units, divide the whole by the total units, then multiply and rebuild the whole. Say it before the first practice set. During timed work, shorten it to four cue words you can recall without stopping.
The step-by-step method
Step 1: Write each named part beside its ratio number so the order cannot drift
Write each named part beside its ratio number so the order cannot drift. Do this on the page, not only in your head. A brief arrow, label, unit, underline or condition note makes the decision inspectable. If you later find an error, you can repair the exact step instead of restarting the entire answer.
At this stage, do not decorate the answer with extra facts. Ask one diagnostic question: “What evidence would make this step wrong?” If you can name a possible failure, check it now. If the failure is absent, continue. This negative check prevents confidence from replacing proof.
Step 2: Add all ratio numbers to find the total number of equal ratio units representing the whole
Add all ratio numbers to find the total number of equal ratio units representing the whole. Do this on the page, not only in your head. A brief arrow, label, unit, underline or condition note makes the decision inspectable. If you later find an error, you can repair the exact step instead of restarting the entire answer.
At this stage, do not decorate the answer with extra facts. Ask one diagnostic question: “What evidence would make this step wrong?” If you can name a possible failure, check it now. If the failure is absent, continue. This negative check prevents confidence from replacing proof.
Step 3: Divide the known whole by the total ratio units to find the value of one unit
Divide the known whole by the total ratio units to find the value of one unit. Do this on the page, not only in your head. A brief arrow, label, unit, underline or condition note makes the decision inspectable. If you later find an error, you can repair the exact step instead of restarting the entire answer.
At this stage, do not decorate the answer with extra facts. Ask one diagnostic question: “What evidence would make this step wrong?” If you can name a possible failure, check it now. If the failure is absent, continue. This negative check prevents confidence from replacing proof.
Step 4: Multiply the unit value by each named ratio number to find the actual parts
Multiply the unit value by each named ratio number to find the actual parts. Do this on the page, not only in your head. A brief arrow, label, unit, underline or condition note makes the decision inspectable. If you later find an error, you can repair the exact step instead of restarting the entire answer.
At this stage, do not decorate the answer with extra facts. Ask one diagnostic question: “What evidence would make this step wrong?” If you can name a possible failure, check it now. If the failure is absent, continue. This negative check prevents confidence from replacing proof.
Step 5: Keep the original quantity unit on every result and test whether whole-number conditions are satisfied
Keep the original quantity unit on every result and test whether whole-number conditions are satisfied. Do this on the page, not only in your head. A brief arrow, label, unit, underline or condition note makes the decision inspectable. If you later find an error, you can repair the exact step instead of restarting the entire answer.
At this stage, do not decorate the answer with extra facts. Ask one diagnostic question: “What evidence would make this step wrong?” If you can name a possible failure, check it now. If the failure is absent, continue. This negative check prevents confidence from replacing proof.
Step 6: Add all reconstructed parts and simplify their ratio to verify both the total and relationship
Add all reconstructed parts and simplify their ratio to verify both the total and relationship. Do this on the page, not only in your head. A brief arrow, label, unit, underline or condition note makes the decision inspectable. If you later find an error, you can repair the exact step instead of restarting the entire answer.
At this stage, do not decorate the answer with extra facts. Ask one diagnostic question: “What evidence would make this step wrong?” If you can name a possible failure, check it now. If the failure is absent, continue. This negative check prevents confidence from replacing proof.
Misconceptions to diagnose and repair
Misconception 1
Tempting move: Dividing the whole by the larger ratio number instead of by the sum of all ratio units. This feels efficient because it removes a decision. It is unsafe because the question may have changed the reference, unit, interval, definition or strength of claim.
Repair: return to the line, number, setup or statement that supplies the condition. Mark it with a short label. Then rebuild only the affected link. Keep all earlier work that remains valid. The purpose of checking is targeted correction, not anxious repetition.
Misconception 2
Tempting move: Treating the difference between ratio numbers as the number of units in the whole. This feels efficient because it removes a decision. It is unsafe because the question may have changed the reference, unit, interval, definition or strength of claim.
Repair: return to the line, number, setup or statement that supplies the condition. Mark it with a short label. Then rebuild only the affected link. Keep all earlier work that remains valid. The purpose of checking is targeted correction, not anxious repetition.
Misconception 3
Tempting move: Swapping labels because the larger actual part looks more important. This feels efficient because it removes a decision. It is unsafe because the question may have changed the reference, unit, interval, definition or strength of claim.
Repair: return to the line, number, setup or statement that supplies the condition. Mark it with a short label. Then rebuild only the affected link. Keep all earlier work that remains valid. The purpose of checking is targeted correction, not anxious repetition.
Misconception 4
Tempting move: Rounding a non-integer unit value when the context requires whole objects. This feels efficient because it removes a decision. It is unsafe because the question may have changed the reference, unit, interval, definition or strength of claim.
Repair: return to the line, number, setup or statement that supplies the condition. Mark it with a short label. Then rebuild only the affected link. Keep all earlier work that remains valid. The purpose of checking is targeted correction, not anxious repetition.
Misconception 5
Tempting move: Stopping after finding one unit and reporting it as one of the requested parts. This feels efficient because it removes a decision. It is unsafe because the question may have changed the reference, unit, interval, definition or strength of claim.
Repair: return to the line, number, setup or statement that supplies the condition. Mark it with a short label. Then rebuild only the affected link. Keep all earlier work that remains valid. The purpose of checking is targeted correction, not anxious repetition.
Eight worked cases
Worked case 1: Two-part sharing
Scenario. Red and blue counters are in the ratio 2:3. There are 25 counters altogether.
The tempting error. Dividing 25 by 3 because three is the larger ratio number. The response may contain relevant knowledge, yet it does not answer the precise decision because one label or condition has been lost.
Work the mechanism. The whole has 2+3=5 ratio units. One unit is 25÷5=5 counters. Red has 2×5 and blue has 3×5. Write the decisive evidence beside the step where it is used. This makes the reasoning readable to another person and prevents a later sentence from quietly changing the meaning.
Answer form. Red=10, blue=15. Check 10+15=25 and 10:15=2:3. Notice that the answer carries both the conclusion and the reason that licenses it. It is complete without becoming a list of everything you know.
Check. Re-read the command word, substitute the conclusion into the original situation and ask whether every noun, number and comparison still has the same referent or unit. If the answer is stronger than the evidence, narrow it.
Delayed transfer. Change the total to 40 and keep the ratio. Do this variation after a gap, not immediately, so retrieval rather than imitation drives the solution.
Worked case 2: Three-part allocation
Scenario. A prize fund is shared among A, B and C in the ratio 2:3:5. The total is $600.
The tempting error. Using only the first two ratio numbers and forgetting C. The response may contain relevant knowledge, yet it does not answer the precise decision because one label or condition has been lost.
Work the mechanism. Total units=2+3+5=10. One unit=$600÷10=$60. Multiply by each labelled part. Write the decisive evidence beside the step where it is used. This makes the reasoning readable to another person and prevents a later sentence from quietly changing the meaning.
Answer form. A=$120, B=$180, C=$300. Notice that the answer carries both the conclusion and the reason that licenses it. It is complete without becoming a list of everything you know.
Check. Re-read the command word, substitute the conclusion into the original situation and ask whether every noun, number and comparison still has the same referent or unit. If the answer is stronger than the evidence, narrow it.
Delayed transfer. Add the three amounts and simplify 120:180:300. Do this variation after a gap, not immediately, so retrieval rather than imitation drives the solution.
Worked case 3: Known whole with units
Scenario. Juice concentrate and water are mixed in the ratio 1:4 to make 750 mL.
The tempting error. Calling one unit 750 mL because the ratio already names five parts. The response may contain relevant knowledge, yet it does not answer the precise decision because one label or condition has been lost.
Work the mechanism. Total units=5. One unit=150 mL. Concentrate is one unit and water is four units. Write the decisive evidence beside the step where it is used. This makes the reasoning readable to another person and prevents a later sentence from quietly changing the meaning.
Answer form. 150 mL concentrate and 600 mL water. Notice that the answer carries both the conclusion and the reason that licenses it. It is complete without becoming a list of everything you know.
Check. Re-read the command word, substitute the conclusion into the original situation and ask whether every noun, number and comparison still has the same referent or unit. If the answer is stronger than the evidence, narrow it.
Delayed transfer. Convert the final total to litres only after the allocation is secure. Do this variation after a gap, not immediately, so retrieval rather than imitation drives the solution.
Worked case 4: Integer feasibility
Scenario. Thirty-two identical stickers are said to be shared in the ratio 3:5.
The tempting error. Rounding after dividing by eight even when division is exact is not needed; or using a total that would not divide exactly. The response may contain relevant knowledge, yet it does not answer the precise decision because one label or condition has been lost.
Work the mechanism. Total units=8, and 32÷8=4 stickers per unit. Whole objects are preserved. Write the decisive evidence beside the step where it is used. This makes the reasoning readable to another person and prevents a later sentence from quietly changing the meaning.
Answer form. The parts are 12 and 20 stickers. Notice that the answer carries both the conclusion and the reason that licenses it. It is complete without becoming a list of everything you know.
Check. Re-read the command word, substitute the conclusion into the original situation and ask whether every noun, number and comparison still has the same referent or unit. If the answer is stronger than the evidence, narrow it.
Delayed transfer. Test a total of 30 and explain why exact whole-number sharing in 3:5 is impossible without changing the conditions. Do this variation after a gap, not immediately, so retrieval rather than imitation drives the solution.
Worked case 5: Difference given, not whole
Scenario. Two groups are in the ratio 3:7 and differ by 24 pupils.
The tempting error. Adding ratio units and dividing 24 by ten as if 24 were the whole. The response may contain relevant knowledge, yet it does not answer the precise decision because one label or condition has been lost.
Work the mechanism. The given 24 corresponds to the difference 7−3=4 ratio units. One unit=24÷4=6. Write the decisive evidence beside the step where it is used. This makes the reasoning readable to another person and prevents a later sentence from quietly changing the meaning.
Answer form. Groups are 18 and 42; their total is 60. Notice that the answer carries both the conclusion and the reason that licenses it. It is complete without becoming a list of everything you know.
Check. Re-read the command word, substitute the conclusion into the original situation and ask whether every noun, number and comparison still has the same referent or unit. If the answer is stronger than the evidence, narrow it.
Delayed transfer. Check the difference and ratio separately. Do this variation after a gap, not immediately, so retrieval rather than imitation drives the solution.
Worked case 6: One part given
Scenario. Boys:girls=4:5 and there are 28 boys.
The tempting error. Adding nine units and dividing 28 by nine. The response may contain relevant knowledge, yet it does not answer the precise decision because one label or condition has been lost.
Work the mechanism. The known boys correspond to four units, not the whole. One unit=28÷4=7. Girls=5×7. Write the decisive evidence beside the step where it is used. This makes the reasoning readable to another person and prevents a later sentence from quietly changing the meaning.
Answer form. There are 35 girls and 63 pupils altogether. Notice that the answer carries both the conclusion and the reason that licenses it. It is complete without becoming a list of everything you know.
Check. Re-read the command word, substitute the conclusion into the original situation and ask whether every noun, number and comparison still has the same referent or unit. If the answer is stronger than the evidence, narrow it.
Delayed transfer. Mark clearly which quantity is the whole before choosing the divisor. Do this variation after a gap, not immediately, so retrieval rather than imitation drives the solution.
Worked case 7: Ratio after a removal
Scenario. Green:yellow=5:3 initially. After 12 green counters are removed, the ratio becomes 3:3.
The tempting error. Using one unit value for both the before and after ratios without tracking the unchanged yellow count. The response may contain relevant knowledge, yet it does not answer the precise decision because one label or condition has been lost.
Work the mechanism. Yellow is unchanged. Initially yellow=3 old units. After removal it equals green and can anchor the new equality. Let one old unit be u: 5u−12=3u. Write the decisive evidence beside the step where it is used. This makes the reasoning readable to another person and prevents a later sentence from quietly changing the meaning.
Answer form. 2u=12, so u=6. Initially green=30 and yellow=18. Notice that the answer carries both the conclusion and the reason that licenses it. It is complete without becoming a list of everything you know.
Check. Re-read the command word, substitute the conclusion into the original situation and ask whether every noun, number and comparison still has the same referent or unit. If the answer is stronger than the evidence, narrow it.
Delayed transfer. Rebuild the after quantities: 18 green and 18 yellow. Do this variation after a gap, not immediately, so retrieval rather than imitation drives the solution.
Worked case 8: Rejecting a false allocation
Scenario. A learner divides 84 in the ratio 2:5 and reports 24 and 60.
The tempting error. Rejecting it because 24 is not 2×12 without checking the full relationship. The response may contain relevant knowledge, yet it does not answer the precise decision because one label or condition has been lost.
Work the mechanism. The whole has seven units; one unit is 12. The parts are exactly 24 and 60. The allocation is valid. Write the decisive evidence beside the step where it is used. This makes the reasoning readable to another person and prevents a later sentence from quietly changing the meaning.
Answer form. Accept it after checking sum 84 and ratio 2:5. Notice that the answer carries both the conclusion and the reason that licenses it. It is complete without becoming a list of everything you know.
Check. Re-read the command word, substitute the conclusion into the original situation and ask whether every noun, number and comparison still has the same referent or unit. If the answer is stronger than the evidence, narrow it.
Delayed transfer. Create a near miss, 25 and 59, and identify both failed checks. Do this variation after a gap, not immediately, so retrieval rather than imitation drives the solution.
Practice progression: from recognition to transfer
Round 1: mark only
Use six short items. Do not answer them. Mark the object, reference, unit, interval, condition or rule that controls the decision. The goal is accurate noticing without the burden of full writing.
Record the result as one of four codes: N for noticing error, M for method error, I for interpretation error, and C for checking error. Practise the weakest code with a fresh item. Do not repeat an entire worksheet when only one decision needs repair.
Round 2: explain the choice
Solve four items and add one sentence beginning “This is valid because…”. If the sentence merely repeats the answer, the condition is still hidden.
Record the result as one of four codes: N for noticing error, M for method error, I for interpretation error, and C for checking error. Practise the weakest code with a fresh item. Do not repeat an entire worksheet when only one decision needs repair.
Round 3: repair a wrong answer
Take four plausible wrong answers. Identify the earliest faulty link, preserve the correct work and rewrite only what must change. This develops error diagnosis rather than answer copying.
Record the result as one of four codes: N for noticing error, M for method error, I for interpretation error, and C for checking error. Practise the weakest code with a fresh item. Do not repeat an entire worksheet when only one decision needs repair.
Round 4: mixed questions
Mix this job with two older skills. Remove headings that reveal the topic. Decide which routine applies before solving. Selection is part of performance.
Record the result as one of four codes: N for noticing error, M for method error, I for interpretation error, and C for checking error. Practise the weakest code with a fresh item. Do not repeat an entire worksheet when only one decision needs repair.
Round 5: timed set
Use a small timed set with a fixed check budget. Mark a cue at the decision point, finish the answer, then perform one positive check and one rejection check.
Record the result as one of four codes: N for noticing error, M for method error, I for interpretation error, and C for checking error. Practise the weakest code with a fresh item. Do not repeat an entire worksheet when only one decision needs repair.
Round 6: delayed transfer
Return after two or three days with different surface details. Before seeing notes, write the one-line rule from memory and solve. Compare the new error pattern with the earlier one.
Record the result as one of four codes: N for noticing error, M for method error, I for interpretation error, and C for checking error. Practise the weakest code with a fresh item. Do not repeat an entire worksheet when only one decision needs repair.
Graded independent practice with explained answers
Practice 1: Foundation
Try it. Share 42 in the ratio 2:5.
Open the answer and explanation after attempting the question
Answer. 12 and 30.
Why. There are seven units; one unit is 6. Multiply by two and five.
Check or transfer. Check 12+30=42 and 12:30=2:5.
Practice 2: Three parts
Try it. Share 96 in the ratio 1:3:4.
Open the answer and explanation after attempting the question
Answer. 12, 36 and 48.
Why. Eight total units make one unit worth 12.
Check or transfer. Add all three answers before accepting them.
Practice 3: Units
Try it. A 1.2 L drink has syrup:water=1:5. Find each amount in mL.
Open the answer and explanation after attempting the question
Answer. 200 mL syrup and 1000 mL water.
Why. Convert 1.2 L to 1200 mL, then divide by six units.
Check or transfer. Rebuild 1200 mL and express it again as 1.2 L.
Practice 4: Given difference
Try it. Two lengths are in ratio 4:9 and differ by 35 cm.
Open the answer and explanation after attempting the question
Answer. 28 cm and 63 cm.
Why. Five ratio units equal 35 cm, so one unit is 7 cm.
Check or transfer. Check the 35 cm difference and 4:9 ratio.
Practice 5: Given part
Try it. Cats:dogs=3:8 and there are 24 cats. How many animals altogether?
Open the answer and explanation after attempting the question
Answer. 88 animals.
Why. Three units equal 24, so one unit is 8; total eleven units equal 88.
Check or transfer. Do not divide 24 by eleven because 24 is not the whole.
Practice 6: Feasibility
Try it. Can 50 indivisible tokens be shared exactly in ratio 3:4?
Open the answer and explanation after attempting the question
Answer. No, not as whole tokens under those conditions.
Why. Seven total units would require 50÷7 tokens per unit, not a whole number.
Check or transfer. State the condition that would make fractional units permissible.
A compact practice log
- Question source and date
- Decision cue you marked
- Your first answer in one line
- Earliest wrong link, if any
- Corrected rule in twelve words or fewer
- Date for delayed transfer
- Whether the new item was solved without notes
A useful log is small enough to maintain. It should help you predict the next mistake, not become a scrapbook of completed pages.
Checking that tests meaning, not neatness
A check should have a target. First run a positive test: identify the evidence, calculation or condition that supports your answer. Then run a rejection test: name the closest tempting alternative and the exact reason it fails. This pair is more powerful than rereading the same line while hoping to feel certain.
Use a reverse check where possible. Reconstruct the original amount, replace a connector with its expanded meaning, map a conclusion back to the data, or apply the repaired rule to the apparent exception. Reverse checking exposes lost labels and unsupported leaps because the answer has to return to its source.
Stop when the check has answered a real question. Repeatedly changing a sound answer because it feels unfamiliar is not checking. If the object, relationship, condition and claim all remain consistent, keep the answer and move on.
Examination control
When time is tight, use the cue ORCC: Object, Relationship, Condition, Claim. Write only the smallest useful mark—an arrow, a unit, a time interval, a boundary or a qualifying word. The mark should prevent the known error without slowing the rest of the paper.
- Read the command word and identify the decision.
- Mark the object or quantity that must keep its identity.
- State the relationship or operation in plain language.
- Check the condition that makes it valid.
- Give the claim at the strength supported by evidence.
- Use one positive and one rejection check, then stop.
If you become stuck, do not produce a longer answer immediately. Shorten the task: write what is known, what must be decided and what condition separates the two best options. A precise partial structure often unlocks the next step and also makes any partial credit more defensible.
A seven-day delayed-transfer plan
- Day 1: learn the one-line rule and complete two worked cases with notes.
- Day 2: solve four short items without notes; classify errors by N, M, I or C.
- Day 3: mix two new items with two older PSLE skills and hide the topic labels.
- Day 4: explain one case aloud to a parent, tutor or imaginary learner in under two minutes.
- Day 5: complete a timed mini-set and use the ORCC marks only at decision points.
- Day 6: rest this skill or practise a different subject so memory has to consolidate.
- Day 7: attempt one unfamiliar transfer item, then write the smallest rule revision needed.
Success on Day 7 matters more than fluency immediately after reading. Delayed transfer shows whether you can retrieve the method, recognise its job under new surface details and control it without a model beside you.
Guidance for parents and tutors
Ask for the decision, not a performance speech. Useful prompts are: “What exactly are you deciding?”, “Which word, unit or condition controls it?”, “What is the closest wrong option?” and “How can you check without starting again?” These questions keep ownership with the learner while making thinking visible.
When an error occurs, locate its earliest point. Praise accurate diagnosis even before the final answer is corrected. If the learner repeatedly loses the same label, introduce one stable notation: arrows for reference, units beside remainders, interval brackets for rates, or boxes around claim conditions. Avoid adding several new routines at once.
Build variation gradually. Begin with clean examples, then add one plausible distractor, then mix the skill with older content, and finally delay the next attempt. A learner who succeeds only when the worksheet title names the method has learned recognition, not transfer.
Keep emotional temperature low. A surprising exception or remainder is information, not proof that the learner is “bad at” a subject. The practical question is which link changed. Once that link is named, practise a small set that isolates it and then return to mixed questions.
The independent-reader test
Before you call the skill secure, explain one solution to a reader who cannot see your thoughts. Name the starting information, the decision, the condition that controls it and the reason the rejected alternative fails. If the explanation depends on “you know what I mean”, a label is still missing. Add that label to the answer, then remove any sentence that does not help the reader follow the chain.
Next, cover the worked example and rebuild the method from a fresh prompt. Do not copy the surface details. Recover the sequence of decisions. This separates genuine control from familiarity with one page. A learner who can transfer the decision routine to new names, numbers or apparatus has a more dependable examination skill than a learner who can reproduce only the model answer.
Finally, compress the method without losing its safety condition. Write one sentence of no more than fifteen words, then test that sentence against an awkward case. If the short rule gives the wrong result, restore the missing condition. Good compression keeps the mechanism available under time pressure while the awkward case prevents the cue from becoming a careless shortcut.
A timed diagnosis drill
Set aside twelve minutes and choose three unfamiliar questions that could trigger this error. Spend the first minute identifying the decision in each question without solving it. Mark the object, relationship, condition and permitted claim. This preview is not wasted time: it prevents you from entering a long method before you know what the method must preserve.
Solve the three questions in the next eight minutes. After each answer, write one tiny prediction about what a correct answer should preserve: a reference word, a whole-number boundary, a pathway, a unit, a direction or an observable result. Then compare the finished answer with that prediction. If they disagree, repair the earliest link and keep the later work only when its meaning remains valid.
Use the final three minutes to classify the errors. A noticing error means the controlling detail was never marked. A method error means the right information was present but the wrong operation or reasoning chain was used. An interpretation error means the result was calculated or observed correctly but described at the wrong level. A checking error means the answer contained a detectable contradiction that the final audit missed.
Repeat the drill a week later with different surface details and without looking at the old corrections. Improvement is not merely a higher score. Look for a shorter pause at the decision point, fewer unnecessary restarts, more stable labels and a clearer reason for rejecting the nearest wrong answer. Those are signs that the performance routine is becoming portable.
Frequently asked questions
What is a ratio unit?
One equal unit in the multiplicative structure represented by the ratio numbers.
Why add the ratio numbers?
When the given quantity is the whole, their sum represents all equal units in that whole.
When should I not add first?
If the known quantity is one part or a difference, match it to the corresponding ratio units first.
Can one unit be a decimal?
Yes for divisible quantities such as money or length, but check whether the context requires whole objects.
How do I stop label swaps?
Write each name directly above or beside its ratio number before calculating.
What are the two final checks?
The parts must rebuild the whole and simplify to the stated ratio.
How does this connect to a ratio table?
A ratio table keeps the same labelled quantities aligned while equivalent pairs scale.
What should I study next?
Use the Mathematics Learning Hub for ratios, fractions, rates, percentages and model methods.
Your next route
Use this guide until you can state the rule, solve an unfamiliar case and explain why the closest alternative fails. Then return to the complete PSLE Learner’s Guide volume directory or move to a deeper subject route: the English Learning Hub, Mathematics Learning Hub, Science Learning Hub, or the full learning-hubs directory. Return to the PSLE Learning Guide when you want to place this skill inside a broader revision sequence.
After identifying the grammatical job in English, this guide preserves the identity of each ratio part and turns a whole into a checked allocation.