Thank you for your email. I understand how confused and concerned you are feeling.
There is a strong possibility that your son may be bored in class as he is ahead in numeracy and literacy and it would be very sad if a bright child was put on medication because his teacher is unable to maintain his interest or provide the enrichment he needs.
I would recommend you have a full assessment including an IQ test done with a qualified educational psychologist. She/he will give you a comprehensive report indicating your son's strengths and weaknesses and recommend any therapies including whether they think he needs a neurological assessment.
If you tell me which area you live in I can give you the names of educational psychologists in your area.
You understand your son well, trust your instincts and research all recommendations that are made thoroughly before considering medication. Medication can help children with severe learning and behaviour problems, but in your case it should be a last resort.
Let me know the results of the assessment and I can advise you further.