There is a "great deal of logic" in targeting the nation's youngest children to return to school first when the coronavirus lockdown lifts, the head of Ofsted has said.
Amanda Spielman said younger pupils need "routine" and, from parents' perspectives, are those who need the most "care and oversight".
In an interview with Sky News's Sophy Ridge on Sunday programme, the Ofsted chief inspector also said it is in all children's best interests that they return to the classroom "as soon as possible", but there is no single "no-brainer answer" on how to do so.
Ms Spielman told the show: "There's a great deal of logic in targeting younger children.
"We know that making normality for children is really important, the younger the children, the more they need that simple structured routine where they understand what's happening.
"It's hard for them to go to school one day and then not for another two weeks. So I entirely recognise and see the logic of this.
"I also think there's a logic from the point of view of parents. The youngest children are the ones who need the greatest care and oversight.
"It's hardest for parents to work and do all the other things they need to do if they're also looking after perhaps several young children at the same time and trying to make sure they work through schoolwork remotely.
"If you look at the interests of children, it's very clear that their interests are best served, in the vast majority of cases, by being back at school as soon as possible."
Ms Spielman said it is in the "hands of the health experts" to say what is safe and how education could be organised, and she "wouldn't want to second guess that for one moment".
She went on to say that she believes many ideas about a return to school are being discussed, adding "as we can see from other countries, there doesn't seem to be one no-brainer answer".
"The harm to children is largely invisible."
Ofsted's @amanda_spielman says the loss of education will "contribute to widening gaps" and the longer children stay out of school the harder it will be to "pull that together".
— Sophy Ridge on Sunday (@RidgeOnSunday) May 3, 2020
Her comments come amid reports that discussions are under way on whether some children, such as the youngest age groups, could return to school early next months.
The Ofsted boss also said questions over how far children could have fallen behind in their education due to being out of school are "really hard" to answer at this point
She highlighted different groups, including pupils with special educational needs, those who struggle to access technology and equipment to take part in schooling from home, those living in "cramped" households and children who "just aren't very motivated", saying "we should be really clear that we don't need to measure precisely which children are being disadvantaged, it's just very clear that a lot are".
Ms Spielman also said it is right that Ofsted is not inspecting the education schools are currently offering, saying the "vast majority" are putting in effort to provide online classes, resources and learning packs for their pupils to study at home and that it would be "wrong" to judge that "in the absence of any clear expectation".