She asked me what maths is for

12 August 2026 · by Larry

Sunday afternoon, halfway down a page of sums. She put the pencil down, looked at me, and said: what is this even for?

Not whining. She wasn't tired and she wasn't stuck. It was a genuine question, asked the way children ask genuine questions — flatly, at the worst possible moment, with an answer expected immediately.

My first answer was rubbish

I said something about needing it for school. For the exams. For later.

She went back to the page and did the rest of it, and I sat there knowing I had just told her the truest thing I could have said and also the least useful. Because think about what that answer actually means to a child: you have to do this boring thing now so that later you can do more of the boring thing, and eventually somebody will give you a grade.

I would not have accepted that answer at seven. I don't accept it at forty-something either. It isn't a reason. It's an instruction wearing a reason's clothes.

The second answer was sitting on the table

We had been out that morning. The receipt was still on the table, so I picked it up and asked her whether the uncle had charged us right.

That was it. That was the whole trick. She took the receipt off me, and I watched her decide she cared.

She checked the prices. She got confused by one line and asked me. She found that two of them were the same item and worked out why. And when she got to the total she wanted to know if it was correct — not because I had asked her to add up, but because she genuinely wanted to know whether we had been short-changed.

Same subtraction. Same carrying. Same child, ten minutes later, doing it without being asked.

What I think was really going on

I don't think she was asking me to justify mathematics. I think she was telling me something, in the only words she had: nothing I am doing on this page has any consequence.

And she was right. Nothing did. If she got it wrong, nothing happened. If she got it right, nothing happened either — a tick, and another one just like it underneath. Twenty-five sums where the only thing at stake is whether you got them right.

A receipt has something at stake. Not much — a dollar, maybe — but it is real, it is ours, and there is an answer nobody in the room already knows. That is a completely different thing from a page where the answer exists in the back of a book and the only person who doesn't know it is you.

What I've changed since

Not much, honestly. I haven't turned our kitchen into a project-based learning centre. But I have started keeping a few of these around, and they cost nothing:

The receipt. Still the best one. Did he charge us right?
Splitting things. Four of us, a packet of something, and one left over. What do we do with the one?
Is it enough? She has some money, she wants two things. She has to work out whether she can, before we get to the counter.
How long more? We're leaving at 4, it's 2.40 now. Her answer, not mine.

None of that replaces practice. She still needs to know her number bonds cold, and that comes from doing them until they stop needing thought. But practice and reason are two different jobs, and I had been trying to make practice do both.

The bit I got wrong for a long time

I used to think a child who asks "what is this for" is looking for a way out. So I would answer briskly and get us both back on task, which is exactly what I did the first time.

I now think it is one of the better questions she asks me, and that the honest answer is not "for the exam" but something closer to: so that you can tell when someone is wrong, including me. That, she liked.

There is a version of this in the word problem post too — she could do the sum, and the same sum in a story stopped her dead. A child who can add is not automatically a child who can see where adding belongs. The receipt is that same gap, approached from the easier side.

And it sits oddly next to why I stopped timing her. The clock taught her that fast is what good looks like. The receipt taught her that right is what good looks like, and that it is worth taking your time over. I know which one I would rather she keeps.

— Larry

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