Hiroshi Kumon, chairman of the Japanese Kumon Institute of Education which offers out-of-school tuition to 40,000 youngsters in the UK, said maths education could not be effectively delivered to groups of 30 children.

The programme is based on ability - it's not age-based

Charlotte Church, Kumon Institute

"If you see 30 students in one class, you have to deal with 30 capabilities. You have to focus on the 15 students in the middle," Mr Kumon told the Independent newspaper.

"Many students will be bored by what they are expected to do and other students still won't be able to catch up."

Mr Kumon's comments come as A-level results to be published on Thursday are expected to show a slump in the number of young people taking maths.

There has also been an 11% drop in applications to study for a maths degree.

Last year the Education Secretary, Estelle Morris, expressed her disappointment that the proportion of 11 year olds achieving the expected level in maths at Key Stage 2 had fallen from 72% in 2000 to 71% in 2001.

And the government was forced to revise its maths targets for 14 year olds from 80% achieving Level 5 - the level expected for their age - to 75%.

Kumon method

The Kumon method, which is used by three million pupils world-wide, uses an individualised system of learning.

The method, which is not without its critics in the teaching profession, assesses each child and gives them suitable exercises to be repeated until they are successful and move on to harder sums.

"The programme is based on ability - it's not age-based," said communications manager Charlotte Church.

"The aim is to boost confidence and it's all done through self-learning.

"The idea is that children score 100% or there abouts and it makes them feel good about themselves."

The system was devised in Japan by Hiroshi Kumon's father, Toru, who was concerned after his son Takeshi scored badly in a math exam.

The methods of Mr Kumon senior, a high school maths teacher, could now be included into the national curriculum in Japan.

The scheme was brought to the UK 11 years ago and has enjoyed a surge of interest in recent years.

In January 2001, the institute had nearly 30,000 youngsters on its books in the UK, by June 2002 the figure stood at 38,542.