The first attendance figures since schools in England returned last week show high levels of pupils back in the classroom.
In primary schools, 95% of pupils were in classes at the end of last week.
The return has been staggered in secondaries to allow Covid testing, but 89% of pupils were in last Monday.
"Certainly for primary schools, the return of all pupils appears to have gone smoothly," said the National Association of Head Teachers.
This is the highest proportion of secondary school pupils in school since the first lockdown began a year ago - with a further 2% waiting for a phased return this week.
Back in class
Secondary schools have been carrying out Covid tests on pupils, screening them as they return, with the attendance figures showing how they were filtered back, with numbers rising from 30% to 89% through the week.
Among the 1% of pupils not in school because of Covid, the greatest numbers were self-isolating because of a potential contact with a positive case.
There were about 12,000 pupils absent because they were a confirmed or suspected case - but 33,000 were self-isolating because of a potential contact in school, such as someone in their bubble, and another 31,000 because of a potential contact at home.
The ASCL head teachers' union leader, Geoff Barton, welcomed the "very high levels of attendance" and said schools "deserve huge credit for setting up what are essentially medical facilities".
But he warned that in terms of future outbreaks in schools, "we are not out of the woods yet".
He added: "We must sound a note of caution over what attendance levels will look like for what remains of this term, because we are picking up reports of positive Covid cases and close contacts having to be sent home to self-isolate."
Paul Whiteman, leader of the National Association of Head Teachers, said he expected the government to "keep a very close eye on the emerging data and assess the impact of the wider re-opening".
Education Secretary Gavin Williamson said he did "not underestimate the preparation that has taken place to ensure our children could return safely".
He added: "It is fantastic to see the overwhelming majority of children have now returned to the classroom, with all the benefits that face-to-face contact with their teachers and friends is proven to bring."