There is widespread confusion about England's new GCSE grading system, says the exams regulator Ofqual. 

Starting this summer, GCSE grades A* to G will be phased out in favour of grades numbered from nine to one. 

However, around 70% of more than 400 parents and pupils surveyed by Ofqual did not understand the system. 

"It is really important we explain the basics, like the fact that nine is the highest grade," said Chief Regulator Sally Collier. 

Ofqual wants to raise awareness of the numerical grading system which starts this summer, with candidates who sit new more challenging English and maths GCSEs receiving a mixture of number and letter grades. 

By the summer of 2018 a mix of numbers and letters will be awarded in an additional 20 subjects, with the letter system entirely phased out by 2019. 

But according to the regulator's small survey, awareness is currently low - only 31% of secondary pupils and 30% of parents said they were clear how the new system worked.