The first question is....so what?
Is the school trying to hold him back because of it?
Is the teacher yelling because of it?
Is he going to get a bad grade?
Is he going to feel badly about himself or math?
The answers to these questions will inform your approach.
Parenting me own son gave me great insight into my inner elementrary school student and let me tell you....she was getting too large a proportion of her self esteem from those smiley stickers and red 100s. It is an interesting thing to notice about oneself!
Anyway...the thing to do is figure out how important it is and how much effort you want to but into being a fake X year old. Do talk to the teacher and get his/her idea of how much effort this is worth at this time and how well the other kids do actually. Be sure you know how well the slowest acceptable kid is doing.
