Every parent has a version of it. A child asks for something in a shop, the answer is no, and the question that follows is the real one: why not?
The instinct is to explain the household budget, which is both true and useless to a six-year-old. What works better is smaller and stranger: give the child a fixed amount of money, and let them meet the limit themselves. The lesson is not arithmetic. It is the discovery that choosing one thing means not choosing another — and that this is ordinary rather than unfair.
Start with a number, not a lecture
A small weekly amount, paid reliably, teaches more than an occasional large gift. Reliability is the whole point: a child who knows the money is coming can plan, and planning is the skill. When the amount is irregular, they optimise for asking instead.
Children who are allowed to make small money mistakes at seven make fewer large ones at seventeen.
The second move is to let the mistake stand. If the money goes on something that breaks in a day, resist replacing it. This is the entire curriculum of Dadi's Gold Rule — earn, save, spend, give — and it only works if spend sometimes goes badly.
Three questions worth asking
Before the money arrives: what are you saving for? After it's spent: was it worth it? And once a month: what would you do differently? None of these need a right answer. They need to be asked in the same tone you'd use about a football match — curious, not testing.
A child who can answer the third question honestly is already doing something most adults avoid.