One in four maths lessons in secondary schools is taught by teachers who have never been trained in the subject.
Figures reveal that at least 750,000 youngsters aged between 11 and 16 are taught maths by untrained staff. Even a rise in the numbers of would-be maths teachers attending training courses is failing to dent the problem, according to Government maths experts.
Many newly trained teachers only last two or three years in the profession before moving on to more lucrative careers in the City or elsewhere in the private sector.
"The behaviour of pupils is often cited as a reason for leaving," said a member of the national literacy and numeracy …