When Your Child Guesses Instead of Working It Out

5 September 2026 · by Larry

You look at the page and there is an answer sitting there on its own. Nothing above it, nothing beside it, no crossing out. You ask how they got it and they say "I just thought it was that."

Sometimes the answer is even right, which makes it harder rather than easier.

The instinct is to say "show your working". It is the correct thing to want and it almost never works as an instruction, because it treats guessing as one habit with one cause. It is not. There are four quite different things going on, they need four different responses, and the first job is telling them apart.

1. They do not know where to start

This is the most common one, and it is the least like laziness.

A child who cannot see a way into the question is left with a blank page and a strong feeling that a blank page is the worst possible outcome. So they put down something plausible. It is not an attempt to cheat the question; it is an attempt to not be the person with nothing written down.

How to tell: it clusters. If you look across a few papers, the guesses land on the same kinds of questions — the two-step ones, or the ones with a fraction of a remainder, or the ones with an unfamiliar shape of sentence. A child who is guessing out of laziness guesses on the easy ones too, because those are the ones that feel most skippable.

What helps: stop asking for the answer and ask what the question is about. "What is happening in this story? Who has what?" Getting them to say it in their own words, out loud, is often enough on its own — and where it is not, it tells you exactly which part is missing. Word problems, when the sums are fine but the story is not goes further into that.

2. They know roughly, and writing it down is slow

This one is genuinely about effort, but not in the way it looks.

For a child who can hold the whole thing in their head, writing working feels like doing the question twice. They are not avoiding thinking. They are avoiding transcription, which to them is the boring part with none of the satisfaction.

The trouble is that it works until it does not. Mental arithmetic that carries a P3 child comfortably starts dropping things when the numbers get bigger and there are three steps to hold at once — and by then the habit of not writing is well established, so the first sign of the problem is marks going down for no visible reason.

What helps: make writing cheap. A lot of children have quietly learned that anything they write must be neat, so they write nothing rather than write something scruffy. Give them a rough page that nobody will look at and say so explicitly. Working is for thinking, not for presentation — which is a different thing from the working that earns method marks, and right answer but the marks still went covers that side of it.

3. Multiple choice, where one option simply looks right

Options are a gift to a guesser, because they turn an open question into a one-in-four bet, and because the wrong options in a good question are the exact mistakes children make — so the wrong one often looks more familiar than the right one.

What helps: cover the options with a hand or a piece of paper, work the question out, write the answer down, then look. It sounds trivial and it changes the task completely, because now the options are a check rather than a menu. It is worth doing this together a few times before expecting them to do it alone.

4. They do not know which operation it is

This is the guess hiding underneath a lot of the others: the child understands the numbers perfectly well but is choosing between plus, minus, times and divide by feel. Often the feel is "the last few questions were times, so this is probably times".

How to tell: the arithmetic is correct and the operation is wrong. That is a very specific signature and it is easy to miss, because at a glance the page looks like a careless error rather than a conceptual one.

What helps: drawing it. A bar model, or even a rough sketch of who has what, turns "which operation" into something visible rather than something to be sensed. Bar models, what they are and how to help is a starting point if that method is new to you.

Why the right guesses are the real problem

Here is the part worth sitting with for a moment.

A lucky right answer and a properly understood right answer look exactly the same on a marked paper. Both get a tick. Neither of you finds out anything.

So the child concludes the topic is fine, you conclude the topic is fine, and the misunderstanding stays in place until it appears in an exam, or in the next topic that builds on it. This is why guessing costs more than the marks it loses — it hides the thing you would have fixed.

The question that works better than "show your working"

Ask "how did you get that?" — and ask it about the right answers, not only the wrong ones.

That second part is the whole trick. If the question only ever appears when something is wrong, it stops being a question and becomes an accusation, and children learn very quickly to brace instead of explain. Asked evenly on a right answer, it is just interest, and it does three things at once: it shows you whether the understanding is real, it gives the child practice at putting a method into words, and it makes explaining ordinary rather than a sign of trouble.

Expect "I don't know, I just knew" at first. That is a fair answer from a child who has never been asked before. Try "have a go — pretend I have never seen this kind of question."

Estimating is not guessing, and it is worth naming the difference

Children often hear "don't guess" as "don't say anything until you are certain", which is not what anyone means and is unhelpful advice for a maths paper.

An estimate is a deliberate rough answer made before the working, so that the real answer has something to be checked against. "It should be a bit under 200." Then, when the working produces 1,940, something is obviously wrong, and they find it themselves rather than being told.

That habit is worth more than most of the advice about carefulness, because it gives a child their own way of catching a mistake — and it is a genuinely different skill from the accuracy problems in careless mistakes and what they usually are.

The guesses are a map

If you keep a couple of papers rather than throwing them out, the pattern shows up quickly. Which topics attract the guesses? Which ones never do?

That map is more useful than a mark. A child guessing consistently on fractions of a remainder, and never on straightforward multiplication, has told you exactly where the next hour of practice should go — and where it would be wasted. It is also a much kinder conversation than one about effort, because you are both looking at a list of topics rather than at their character.

When guessing is the right thing to do

Worth telling them plainly, because otherwise the message they take away is that guessing is naughty.

In the last few minutes of a paper, with an unanswered question, guessing is correct. A blank scores nothing and a guess might score something. The rule is about when: guessing is a last resort at the end, not a first move at the start. Children handle that distinction perfectly well once someone says it out loud.

And what not to do

Try not to make it a question of character. "You're being lazy" and "you didn't even try" land as verdicts on the child rather than on the habit, and the reliable result is that they get better at hiding it — writing plausible-looking working after deciding the answer, which is worse for everyone and much harder to spot.

The habit is fixable. It is mostly about making the thinking visible often enough, and calmly enough, that showing it stops feeling like being caught. If homework is already a flashpoint in your house, checking maths homework without a fight is probably the more useful place to begin.

And if the answers are blank rather than guessed, that is a different problem with a different fix — when your child freezes on a question they know covers work that never got started at all.