Very good points by all above. One thing I wonder about is that you talk about his writing and then you say he does not complete his classwork. Really two different things. Not completing classwork is one thing. Not doing writing instruction is another. Does he have trouble staying on task? Is he easily distracted?
Hi there. Well, fine motor difficulties are a common issue with what you describe and a smart child will avoid it because it is hard for them. We sought occupational therapy to help with this. my son also had eating issues and difficulty chewing (if that rings a bell with what you describe with slow eating). That is also motor related. He had a hard time with any new task such as the first times he used scissors.
We used a hand writing program that helped called "Handwriting without tears". They start very basic and kids seem to relate to the program. we got supplies such as a work book at a teachers supply store and I've seen them sold on ebay.
Also, strengthening the wrist and hand muscles is essential. Kids playing with playdoh is very helpful. And put up a large coloring sheet taped to the wall at his height so he has to stand and use his wrist to color. It will be tiring for him as he develops these muscles.
Sometimes a tool called a slant board helps with kids who don't like to write, pencil grips, little pencils like you use in miniature golf help with hand writing, etc.
If it seems to be a real issue, do consult with an occupational therapist. good luck
As he can write, but is very slow and does not complete his work, it may be worth considering getting him assessed to find out the reason why he is not completing his writing work at school.
Some children that have dyslexia and very slow at righting.
I presume his vision is OK.