Children who start school at five years old with poor maths skills are often doomed to failure, struggling to keep up in class and never able to regain the ground lost at such an early stage.
This failure at maths is partly as a result of pupils at low level sets being given the weakest teachers, according to a report out today.
In addition, thousands of the brightest maths pupil fail to go on and get an A* or A level grade at GCSE because they are put in for the exam too early.
Schools which routinely enter students for GCSE maths early are hindering their ability to reach the highest grades. They end up with a C grade – leaving them ill-equipped to pursue the subject at A-level – because of their school's desire to bank as many A* to C grade passes as possible to bolster its league table position, says the report by Ofsted, the education standards watchdog.
The study follows a report earlier this year which showed that almost half the adults in England only have the maths skills of a primary school child.
The study by National Numeracy – a new independent national charity – showed the number of adults struggling to add up had increased from 15 million to 17 million in the last eight years.
"Too many pupils who have a poor start or fall behind early in their maths never catch up," said Sir Michael Wilshaw, the chief inspector of schools in a foreword to the report.
Too often they find group teaching is pitched at middle attainers and therefore beyond their grasp.
In all, 10 per cent fail to reach the required standard at seven – rising to 20 per cent at 11 and 36 per cent failing to get a C grade at GCSE.
In addition, 37,000 pupils who reach a higher standard than required at 11 fail to get higher than a C grade at GCSE.
"Children's varying pre-school experiences of mathematics mean they start school with different levels of knowledge of number and shape," the report says. "For too many pupils, this gap is never overcome."
"Low attainment too often becomes a self-fulfiling prophecy. Pupils known to be eligible for free school meals fare particularly badly."
It adds: "Some three and four-year-olds can already count and recognise the digits for the first few numbers. Many are familiar with rhymes and songs that involve counting... The gap between what different children know and can do mathematically is present before they start learning at school.
"Years later, when pupils leave compulsory education aged 16 years, the gap between the mathematical outcomes of the highest and lowest attainers is vast. Many more pupils could gain the highest grades at GCSE and be better prepared to continue to A-level.
"Without this, the future supply of mathematicians and the national challenge of meeting the diverse mathematical needs of our technologically advanced world and our economic well-being are threatened."
It warns that "less experienced, temporary and non-specialist teachers were more likely to teach the lower sets or younger pupils."
The report also reveals that white British pupils are more likely to struggle at maths than most other ethnic groups – with just 62 per cent and 63 per cent making the progress expected in the subject by 11 and 16 respectively – compared with 95 per cent of Chinese pupils and 89 per cent and 84 per cent of Indian pupils.
Sir Michael vowed that Ofsted would help schools improve their maths teaching and become more ambitious in their targets for pupils.