In Birmingham, one of the largest areas to test the numeracy strategy, pupils in the pilot schools made greater progress in both maths and English than others in the authority.
According to Birmingham's assessment unit, the 77 schools that introduced a daily maths lesson improved their maths results over a year by two percentage points. Average scores across the city fell by 1.7 percentage points. and maths scores nationally declined by 3.4 percentage points.
However, the same schools also saw a sharp improvement in their English results which rose by 5 percentage points, compared with 3.5 percentage points across the city's primary schools. Nationally English scores improved by only 1.6 percentage points.
David Bartlett, Birmingham's assessment co-ordinator, believes the numeracy strategy is encouraging teachers to revise their approach to other subjects.
"It may also be that pupils are experiencing success in maths and that has an impact on overall achievement," he said.
An analysis by Hackney, east London, produces a similar pattern. The 14 primaries that have piloted the numeracy strategy for two years improved their maths results by 3 percentage points, compared with a five-point drop in results in the 20 schools not in the project. The average across Hackney schools fell by 1.3 percentage points.
Progress in English was also striking. The 14 schools in the maths project for two years improved their results by 6.8 percentage points; the 19 in the scheme for one year improved by 7.3 percentage points. In contrast English scores in Hackney's other 20 schools declined slightly.
Anita Straker, director of the National Numeracy Strategy, said the impact on English had been noticed when the scheme was evaluated.
"It may be that emphasis on oral work benefits children's spoken English. It could also be that the emphasis on well-structured lessons is having an effect on other subjects," she said.
The results might also, she said, be a reflection of the fact that the sample of schools selected was weighted in favour of those that had large numbers of children with English as a second language.
The strategy is being piloted in 18 local education authorities. The 800 schools are weighted in favour of those with low maths results and high levels of deprivation. Ministers are relying on the strategy to get 75 per cent of 11-year-olds achieving target levels by 2002.