The education watchdog says that a significant amount of teaching time is being lost because of a 'casual acceptance' of disruptive pupils and also that primary kids are missing out on a 'broad and balanced' curriculum.
On the issue of behaviour, Chief inspector Sir Michael Wilshaw says children's chances of being taught in orderly classrooms have descended into 'something of a lottery' and that large numbers of lessons are being disrupted on a daily basis by pupils making silly comments to grab attention, swinging on chairs, passing notes around, quietly humming and using mobile phones.
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In a major report to be published this week, Sir Michael insists that strong leadership is the key to cracking down on bad behaviour, warning against a 'casual culture of acceptance' of the problem.
The report uses evidence from almost 3,000 inspections of state schools this year alongside two-specially commissioned surveys of parents and teachers.
In the report, shown to the Telegraph, the watchdog says: "A majority of teachers questioned for the survey said that low-level disruption was prevalent in their classrooms, with the impact on learning most serious in secondary schools.
"Many teachers also complained that school leaders are failing to assert their authority when dealing with poor discipline and pupils flouting the school rules."
Turning to English and maths in primary schools, Ofsted says it's considering reforming the inspections process because an overemphasis on the three-Rs often came at the expense of children's understanding of other subjects.
Mike Cladingbowl, Ofsted's director of school standards, said the watchdog needed to be sure that it had struck the right balance between English and maths and other subjects such as art, music, history and geography.
Speaking to the Times Educational Supplement, Mr Cladingbowl said: "We must continue to emphasise the importance of English and maths, but we should not do that at the expense of other subjects.
"There will be certain circumstances where it's right for children to be given additional help with English and maths at the expense of something else, to get them to a point at which they can access the curriculum properly. "But, through our consultation, we'll want people to ask themselves searching questions about to what extend that should happen. At what point should it stop?"
He said Ofsted now favoured a 'broad and balanced' curriculum that did not 'limit children's experiences or... fail to prepare children for secondary school or life in modern Britain'.
He added: "We want to look and see if we've got the balance right between the core subjects and the foundation subjects; between English and mathematics, and art, history, music, geography and so on."
Head teachers' leaders warned that any rebalancing of the inspections system would fail because SATs tests taken by all 11-year-olds are based around performance in the core subjects – forcing schools to give them a higher priority in the timetable.
Russell Hobby, general secretary of the National Association of Head Teachers, said: "What Ofsted focuses on tends to get done, but floor standards for English and maths are still a powerful driver that is out of Ofsted's control."
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