This year the Government has introduced a new GCSE grading system for maths and English. It uses a 9-1 scale instead of A*-G with 4 being equivalent to a C and 7 being equivalent to an A. The rest of the grades do not map across exactly though. For the current year 10 most subjects use the new grading system and for year 9 virtually all do. If you want to find out more, the official website explaining it is here: New GCSE 9-1 grades.