Too many pupils lack maths skills because of a failure to ensure smooth transition between primary and secondary schools, according to a think-tank which will next week demand a new drive to improve numeracy.
Children who struggle with numbers are twice as likely to be excluded from school and twice as likely to be unemployed, New Philanthropy Capital says.
Its report, to be published next Tuesday, will call for the formation of a new National Numeracy Trust - in the style of the National Literacy Trust (NLT) - to keep the issue high on the political agenda.
Belinda Vernon, one of the authors, said the problem was rooted in an abrupt change in the style of maths teaching at the start of secondary school that left some pupils struggling to adjust.
"In primary schools the way that children are taught seems to be more effective in helping children that struggle," she said.
"They will get a lot of one-to-one support and help to learn in ways that are more motivating. But when they get to secondary school something funny happens and there is a disconnect between the way secondary and primary pupils get taught. It all suddenly becomes more abstract."
She said this "lack of co-ordination" was highlighted by the gap between the 79 per cent of pupils who achieved the expected level in maths aged 11 and the 56 per cent who achieved an A*-C maths GCSE.
NUT head of education John Bangs said: "The transfer remains the longstanding issue. Precious little practical space has been given to primary and secondary teachers to meet and discuss what they have been teaching.
"I don't blame teachers. I blame the way the National Strategies were organised with everything phase related."
The report is expected to argue that there has been no overarching Government strategy to improve maths teaching across all ages, including adults, in a co-ordinated way.
"People are happy to admit if they dislike maths and struggle with it, in a way that is more acceptable than admitting to having problems with reading and writing," it is expected to say.
The think-tank believes that the Government focus on raising test and exam results in maths may have been at the expense of ensuring pupils are "fully comfortable" with using numbers.
It will call on charities to fund a new trust to campaign and lobby for improved numeracy in the same way that the NLT has done for literacy.