PSLE topic guides › Maths › Heuristics

PSLE Heuristics — how to do heuristics questions, and the mistakes that cost marks

Maths · 10 practice questions in the free bank

PSLE Heuristics: quick answers for parents

The short version, then the full guide below.

SubjectMaths · Singapore PSLE
LevelPrimary 5 and Primary 6
Free questions on Heuristics10 in the free month bank, each marked step by step
How the work is markedStep by step — the written steps are marked separately, so you can see which step broke
Written workingIncluded — the bank has written workings, not only multiple-choice questions
CostFree for your first month. No signup and no card
Exam year2026 PSLE

Practise Heuristics free →

Or take the free 3-minute diagnostic to see which Maths topics are actually weak before spending time on Heuristics.

What Heuristics means in the PSLE

Heuristics is a tested maths topic in the Singapore PSLE. The marks are not usually lost because a child does not know the method — they are lost in one specific step, and because nobody can tell the child which step went wrong, the same mistake repeats.

A real Heuristics question, worked step by step

Question (4 marks): A tank was full of water. Sam poured out 1/3 of the water, then poured out another 12 litres. 28 litres of water were left. How much water was in the tank at first?
Step 1 — How much water was in the tank just before Sam poured out the 12 litres?

Work backwards from the end: 28 litres left + the 12 litres poured out.

Where children go wrong: Starting from 28 litres and working forwards. The 12 litres were poured out BEFORE the 28 were left.
Step 2 — 40 litres is 2/3 of the tank, because 1/3 had already been poured out. How much is 1/3 of the tank?

2/3 is 40 litres, so 1/3 = 40 / 2.

Where children go wrong: Dividing 40 by 3. The 40 litres is the 2/3 that is left, so halve it to find 1/3.
Step 3 — How much water was in the tank at first?

The full tank is 3 parts of 20 litres: 3 x 20.

Where children go wrong: Answering 40 litres. That is the water left before the 12 litres, not the full tank.

Why the wrong answer looks right

Question: There are 20 vehicles in a car park. Some are cars with 4 wheels and the rest are motorcycles with 2 wheels. The total number of wheels is 64. How many cars are there?

Options: a) 8 · b) 10 · c) 12 · d) 16

Correct answer: C

Choosing A: 8 is the number of motorcycles, not cars. After finding them, subtract from the total: 20 - 8 = 12 cars.
Instead: Check: 12 cars x 4 wheels + 8 motorcycles x 2 = 48 + 16 = 64 wheels.
Choosing B: You guessed 10 cars and 10 motorcycles. That gives 10 x 4 + 10 x 2 = 60 wheels, which is 4 short of 64.
Instead: Each swap of a motorcycle for a car adds 2 wheels, so swap 4 ÷ 2 = 2: cars = 12.

How to help your child with Heuristics at home

Five things that work, and they use the same method as the worked example above.

1. Get the steps said out loud before anything is written

Marks in Heuristics are usually lost in one step, not across the whole question. Ask your child to say each step before writing it — a broken step is much easier to catch when you can hear it.

2. Mark the working, not just the final answer

A tick or a cross on the last line tells you nothing about where the thinking broke. Read the working line by line and ask, for each line, what it was for.

3. Name the step that broke, in your child's own words

One sentence is enough. Name the step rather than the topic — “I divided before finding one part” tells you what to fix next; “I am bad at Heuristics” does not.

4. Keep the sets short

The free bank has 10 Heuristics questions, marked step by step, and it needs no signup. A short set with the working marked tells you more than a long page of answers.

5. “Careless” mistakes are usually one repeated step

When the same mark keeps disappearing it is rarely carelessness at random — it is one step done the same wrong way each time. Read a week of working and look for the line that is identical and wrong; that is the step to fix.

Practise Heuristics free

Every question in this topic is marked step by step, so when your child goes wrong you can both see exactly which step broke. No signup.

Practise Heuristics free →

Or take the free 3-minute diagnostic to see which topics are actually weak.

Questions parents ask about Heuristics

Is Heuristics tested in the PSLE?

Yes — Heuristics is a Maths topic in the Singapore PSLE, and the free Kyly Tuition bank holds 10 questions on it for P5 and P6 pupils.

Why do children lose marks in Heuristics?

Usually not because they do not know the method. They lose marks in one specific step, and because the mistake is never identified, they practise more of the same and repeat it.

Is the practice free?

Yes. The daily drills are free in all four subjects for your first month, with no signup and no card required. The free diagnostic is also free.

Does this cover Paper 2?

Yes. The bank includes step-marked written problem sums, not only multiple-choice questions, and each step is marked separately.

How do I help my child with Heuristics at home?

Mark the working, not just the answer, and name the one step that broke. The guide above walks through a real Heuristics question step by step, and the free bank marks each written step separately, so you can see which step went wrong instead of only seeing that the answer is wrong.

How many free Heuristics questions are there?

10 questions on Heuristics are in the free Kyly Tuition bank, each marked step by step, with no signup and no card.

Where do children usually lose marks in Heuristics?

Usually in one specific step rather than across the whole question. The worked example above shows a real Heuristics question and flags the step children break on it.

Is PSLE Maths Paper 2 written working included?

Yes. Maths Paper 2 is the written-working paper rather than multiple choice, and the free bank includes those written sums. Each step is marked separately, so a correct method that slips in one step still shows exactly where it went wrong.

Why does my child keep making careless mistakes in PSLE Maths?

'Careless' mistakes are usually not random — the same step is done the same wrong way each time. Read a few days of working and look for the line that is identical and wrong; fixing that one step is what moves the mark. Every question in the free bank is marked step by step, so a repeated step shows up.

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