From a parental perspective our story is more about a fight against high tides in our society. Yes, fighting for some new methods such as QEEG scan of the brain to be recognised as a very helpful tool, is unbelievably hard but rewarding. Fighting with school in time of no financial resources for school assessment to get extra time for exam is more challenging but possible.
Parenting strategies might be to support your teenager to do what he/she loves to do. If Maths is the weakest point, take it slowly with fun and do not worry. There are better things to do. Focus on what he/she loves to do. If staying home is what they want, do some activities/chores home together- gaming, washing dishes and chatting like a chatter box together.
Teach independence and not eating too many sweets with junk food. Remind things and better stay home to wake them up and go to school/or give a lift in the morning. Give earphones to block the people or focus better on homework if wanted. Give them PEACE.