Major reforms to GCSE and A-level maths may not boost the numbers of teenagers studying the subject and could turn young people off, according to research.
The changes, which include toughening up GCSE maths, separating AS from A-levels and bringing in end-of-course exams could discourage youngsters from taking the subject after the age of 16, a report by the Nuffield Foundation says.
The study, which examines maths after age 16 and how to boost the numbers continuing the key subject, notes that from 2016, AS-level maths will be a stand-alone course, and will not count towards a final A-level grade.
But it argues that the "modular" structure of A-levels, including AS-level, has helped to increase the numbers taking maths over the past eight years, in part because students are able to see how they are performing as they complete each module throughout their course, which builds their confidence.
The Government's exam reforms, which will see a move away from modules to exams at the end, are an attempt to end a "re-sit culture", the study says.
But it adds: "There is a danger that a move to a less flexible model may result in a decrease in student numbers. For example, students who are not confident about committing to A-level mathematics or further mathematics from the start may choose not to embark on the qualifications."
The study argues that students are "highly rational" in their choice of A-level subjects, since their results determine their future at university.
Of those taking A-level maths, around 91% gained a top grade at GCSE, and the majority of those who got one of these grades already go on to study maths at least at AS-level.
Those with B or C grades in GCSE maths are less likely to get a good result at A-level and are less likely to choose it, or are discouraged from choosing it.
The move to bring in a new tougher GCSE maths qualification next year could make it more difficult for teenagers to get a top grade and go on to take the subject after the age of 16, the Foundation argues.
The study does back the Government's new "core maths" qualification, which is aimed at students who get a C or better at GCSE, but do not currently take an A-level in the subject.
But it also warns that the timescale for introducing the course is rushed.
For the qualification to be successful, and increase the numbers of youngsters studying maths, it needs strong backing from universities and employers, marketing by exam boards and cross-party political support, the study says.
It suggests that evidence from other countries shows that one of the strongest incentives for teenagers to continue with maths is because they need it to go to university.
Universities could do more to endorse maths, as well as highlighting the mathematical requirements of degree courses and the benefits for youngsters with decent maths skills.
Report author Josh Hillman said: "There is overwhelming evidence that large swathes of students do not have the necessary quantitative skills for higher education and employment.
"But that won't change until the higher education sector as a whole backs the range of post-16 maths qualifications and moves towards making them a requirement for undergraduate admissions. Whether universities will value the new core maths qualification if it is not an AS-level remains to be seen."
The study comes amid a major drive by government to boost take-up of maths after GCSE, particularly among girls.
Skills Minister Matthew Hancock has today announced that top graduates who teach maths in colleges and for training providers will receive "golden hellos" of up to £10,000.
Under the latest reforms, from 2017, new GCSEs in English and maths will become standard qualifications for 16 to 19-year-olds at colleges, training centres and school sixth-forms who did not
get at least a C in the subjects by age 16.
Mr Hancock said: "It is vital that all young people leave education with good literacy and numeracy.
This is part of our long-term economic plan.
"To support colleges and training providers to deliver this, we are investing millions of pounds through our workforce strategy and attracting the brightest and best graduates with the new golden hello scheme."
A Department for Education spokesperson said: "We are pleased the Nuffield Foundation has welcomed the new 'Core Maths' qualification and recognised the importance of offering young people an alternative to AS and A levels.
"Core maths will give more than 200,000 students another option to keep studying maths, using it to solve real life problems and learn the skills that will lead to the highest earnings and the best protection against unemployment.
"By making maths GCSEs and A levels more demanding and removing the endless treadmill of testing, we are ensuring young people can study the subject in more depth, gain greater understanding and be confident that they are learning the skills required by employers and universities alike."