A course that maths teachers said made them "feel clever again" could become a model for professional development in other subjects.
The Teaching Advanced Mathematics programme was designed to prepare staff to teach A-level.
Mathematics in Education and Industry (MEI), the curriculum development body that has been running the scheme since 2003, said it believed the programme could be the first step in the Government's drive to make teaching a masters-level profession.
Under the programme, maths teachers visit one of four universities for study days, as well as accessing web-based study materials and completing fortnightly lessons in an online classroom. They also receive email study support from tutors based at the university or at MEI.
The course, completed mainly in teachers' spare time, typically takes just over a year and leads to a postgraduate certificate in A-level mathematics pedagogy, worth one-third of a masters qualification.
Those who took part were surveyed by MEI and the National Centre for Excellence in the Teaching of Mathematics. Many said the course had boosted their confidence. One said it had made them "feel clever again". Another said: "It gave me the confidence to face students who might be better than me."
Some 90 per cent of the 103 teachers who have completed the course had not previously taught beyond GCSE level. But a survey of 75 of the participants found that 80 per cent were now teaching A-level maths. Twelve reported having taken on roles of responsibility after completing the course.
It also appears to have improved their understanding of higher-tier GCSE maths. The report said the course had helped them understand the connections between topics and why they were taught.
One teacher said: "The course allowed space and time for me to ask how and why, and to get answers that allowed me to pull together many mathematical concepts for the first time."
The Government's new masters qualification in teaching and learning is being introduced next year.
Ed Balls, Schools Secretary, has said he hopes all teachers will complete it within the first five years of their careers.
Meanwhile, 60 teachers attended another well-received course, the National Mathematics Teachers' Summer School at Robinson College in Cambridge last week.
The residential programme offered the chance to engage with advanced mathematical ideas in the last week of the summer holidays.