special consideration GCSE MATHS overall grade

I would like to give information to those who are doing GCSE maths and have unfortunately missed their exam. first you must've done at least one of the 2 exam either cal or non calc. once you have completed 50% then you could be given special consideration based on your circumstances in this case whatever you get for the exam that you have done will be multiplied by 2 to give you your final grade. for example if you get 73% on the exam that you do then it will be multiplied by 2 and your final grade including the one that you haven't done will be 146/200 which if foundation is a C. And thats it!!!!!.