Rishi Sunak claims that England is out of step with the rest of the developed world by not requiring young people to continue studying maths until the age of 18 – but making his numbers add up will need large sums of money and teachers.

Previewing Sunak’s announcement, No 10 argued that England “remains one of the only countries in the world to not to require children to study some form of maths up to the age of 18”, mentioning Australia, Canada, France, Germany, Finland, Japan, Norway and the US as those that did.

But while some countries insist on children continuing with maths in some form until they leave school, some of the others cited only apply the requirement to those in particular strands of secondary Education or do so only in the initial stages.

A 2017 report commissioned by the Department for Education listed Russia, Japan and Sweden as among those where all children continued taking maths, with Canada, France and Germany as having “most” children, 81-94%, enrolled. Further down came Singapore and Hong Kong, countries that rank highly in international comparisons of maths attainment.

In other countries, such as the US and Australia, curriculum requirements and compulsory education vary between states, making it difficult to form national comparisons.

But what is certain is that England has a relatively low rate of school pupils continuing with maths past the age of 16. Roughly half of those who remain in English schools or colleges continue to take maths classes, split between those who take advanced “level 3” courses such as maths or maths-based subjects such as engineering or physics, and a larger group compelled to do so because they failed to gain a 4 or higher in their maths GCSE results.

What that leaves is about 200,000 students in each year group who do well enough in GCSE maths but don’t take courses requiring any maths teaching in years 12 and 13.

But that doesn’t include “all children” – Catherine Sezen, the Association of Colleges education director, says that about 15% of the post-16 year groups are in work, on apprenticeships or have dropped out of education, employment or training entirely.

“It is right that the prime minister is taking an interest in education for 16- to 18-year-olds, but speeches are the easy part. Progress needs an implementation plan based on evidence, backed by appropriate funding and not ignoring huge swathes of young people,” Sezen said.

Sunak certainly isn’t the first minister to consider the issue. In 2011 the government, with Michael Gove as education secretary, commissioned Carol Vorderman to head a taskforce on maths in schools. It recommended that some form of maths teaching remain compulsory until the age of 18.

The government’s eventual answer was a new post-16 qualification for those who wanted it, known as core maths, focusing on topics such as statistics rather than the heavy mechanics of A-levels. But with no incentive to take the course, students have largely avoided it – just 12,000 entered core maths qualifications in 2021.

By 2017 the government had another report to consider, a review of post-16 mathematics by Sir Adrian Smith, a celebrated statistician who is now president of the Royal Society.

“My clear conclusion is that we do not yet have the appropriate range of pathways available or the capacity to deliver the required volume and range of teaching” for students to continue past 16, Smith wrote, adding that substantial changes would be needed to make it possible within a decade.

Five years later and those changes have not occurred: the problems Smith identified in a lack of resources and qualified maths teachers remain. As Bridget Phillipson, the shadow education secretary, points out, recruitment is 5,000 below the government’s targets over the past decade, with many shortages being filled by teachers lacking maths degrees.

Meanwhile, funding for sixth forms and further education colleges – which would carry the heaviest load in extended maths teaching – remains 20% below those of other schools “for no good reason”, according to Sezen.

Responding to Sunak’s announcement, Smith said: “If we want our economy to thrive and young people to be prepared for well-paid jobs, we need a radical overhaul of our education system that will include all young people doing some level of maths to 18 years of age. The prime minister understands this and today’s announcement is welcome.”