The Home Learning / Helping Without Taking Over
Ask them to explain it back to you
Saying something aloud is one of the most reliable ways to find out whether you know it.
There is a large gap between recognising an explanation and being able to give one. A child who nods along while a parent talks will often believe they have understood, and so will the parent, and both will be surprised the following week. Asking the child to say it back closes that gap immediately. Tell me how you would do the next one. Explain that to me as if I had not been listening. Pretend I am your younger cousin and I have no idea what any of this means. The gaps show up in the first sentence, and they show up in the child's own words rather than yours.
This is one of the most consistently supported ideas in how people learn, and it costs nothing. Retrieving something from memory and putting it into your own language does more to fix it in place than reading it again, and it is far more useful than simply feeling familiar with the page. It also gives the child something valuable: the experience of being the one who explains. That is a genuinely different position to be in, and children tend to sit up in it. It is worth doing on the good days as well as the difficult ones, because a child who can only explain the things they have just been rescued from never gets to hear themselves sound competent.
Do not correct the first stumble. Let the explanation run, even when it wanders, because the wandering is the child sorting it out in real time. If it comes out muddled, ask one question about the muddled part rather than restating the whole thing. And if it comes out clearly, say so plainly. A child who has just explained something well has evidence that they understood it, which is worth more than being told they are clever. That evidence is the useful part. It belongs to the child, it does not depend on your opinion of them, and it is available again the next time they are not sure whether they understand something.