Heuristics are the problem-solving methods a PSLE Math student uses to crack a word problem they have not seen before, and model drawing, the bar model, is the one that carries the most marks across the paper. A child who can recognise which method a question calls for, and apply it cleanly, solves the hard problem sums that decide the grade. A child who jumps straight to arithmetic stalls on exactly those questions.
Here is what the methods are, why they matter, and how a parent can coach them without being a maths expert.
What the heuristics are
The Ministry of Education groups problem-solving heuristics into a small number of families. The ones that earn the most marks at PSLE are these:
| Method | When it fits |
|---|---|
| Draw a model (bar model) | Fractions, ratio, comparison, before-and-after |
| Draw a diagram or table | Patterns, organised information, before-and-after states |
| Make a systematic list | Counting possibilities without missing any |
| Guess and check | When working backwards from an answer is faster |
| Work backwards | Problems that give the end state and ask for the start |
| Use a supposition (assumption) | Two-variable problems with a total, the hardest family |
A child does not need to name all of these on demand. They need to recognise, on reading a question, which family it belongs to, and reach for the right tool.
Why model drawing carries the paper
Model drawing is the most frequently used heuristic at PSLE because it applies across so many topics: fractions, ratios, percentages and comparison word problems all yield to a bar model. The model turns an abstract relationship into something a child can see, and once they can see it, the arithmetic usually falls out in a line or two.
The instruction that matters most is this: draw the model before any arithmetic, every time, even when the answer seems obvious. A child who skips the model on a hard question is gambling four or five marks to save thirty seconds. That trade is the difference between AL1 and AL3. Our PSLE Mathematics guide lists the topics where model drawing does the heavy lifting.
A worked example: fractions
Take this question. "Raju had some stickers. He gave one quarter to his sister and 18 to his friend. He had half of his stickers left. How many did he start with?"
A child who jumps to arithmetic flounders. A child who draws a bar, splits it into quarters, marks the quarter given to the sister and the half left over, sees that the 18 stickers must fill the remaining quarter. So 18 is one quarter, and the total is 72. Two lines, because the model did the thinking.
A worked example: before-and-after ratio
"The ratio of John's money to Mary's was 5 to 3. After John spent 20 dollars, the ratio became 3 to 3. How much did John have at first?"
A child who tries to reason it in words usually stalls. A child who draws two bars, one for before and one for after, sees that the units John lost equal 20 dollars. Working from there, one unit is 10 dollars, so John started with 5 units, or 50 dollars. The model is not decoration. It is the method.
Why method marks change the stakes
PSLE Math Paper 2 awards method marks. A child who identifies the right heuristic and shows a clear, labelled setup can earn two or three marks on a question even if the final arithmetic slips. A child who writes only answers throws that partial credit away. So the heuristic is not only about getting the answer. It is about banking marks on the way to it, including on questions a child cannot fully finish.
How a parent can coach this at home
You do not need to solve the problem yourself. The most useful thing you can do is build the naming habit. When your child meets a word problem, ask them to name the method they plan to use before they start calculating: "is this a model question, a working-backwards question, a guess-and-check question?" Identifying the family is most of the battle, and it is a skill you can prompt without doing any maths.
The assumption, or supposition, method is the one children find hardest, because the adjustment step is not intuitive. If a child is shaky there, that is usually the highest-value place to put practice.
Which method each topic tends to need
Recognising the method is most of the battle, and certain topics signal their method fairly reliably. This table gives a child a starting instinct for what to reach for.
| Topic or clue in the question | Method that usually fits |
|---|---|
| Fractions, ratio, percentage, comparison | Draw a model (bar model) |
| A repeating number or shape pattern | Draw a table and find the rule |
| "How many ways" or "list all the.." | Make a systematic list |
| Two quantities sharing a total | Supposition (assumption) |
| The end state is given, the start is asked | Work backwards |
Treat the right column as a first guess, not a rule. The aim is to build the instinct that reading the question comes before reaching for the calculator, because the method, once chosen, usually makes the arithmetic short.
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