England's exams watchdog, Ofqual, said large-scale testing was part of a research programme into the new GCSEs.
The issue centres around sample papers produced by the AQA exam board, and accredited by Ofqual, which rival boards Edexcel and OCR say were not challenging enough.
AQA has insisted its qualification is rigorous, provides a high value assessment and promotes good teaching and learning.
In response, Ofqual has written to all schools asking if they would be prepared to take part in research looking at the difficulty and demand of the new maths GCSEs.
In a paper on the plan, Ofqual said: "To evaluate the actual difficulty of questions, current Year 11 students will be asked to sit one of the question papers from the sample assessment materials as a mock exam. As an incentive to participate, the scripts will be marked and teachers provided with student and item level analyses following the study."
However, the watchdog acknowledged that there would be "some content that pupils are not likely to be fully prepared for" as the exam is based on the forthcoming maths syllabus.
Ofqual said the papers would be sat under exam conditions with a minimum of 500 students per exam paper at each tier of the exam (foundation and higher).
An Ofqual spokeswoman added it had been working with exam boards over the past 18 months to deliver the government's policy aims for the revised GCSE maths qualifications.
