Appleton, each of my kids went through an adjustment when they hit the stage where they really needed to start paying attention to neatness and writing down steps in order to not miss getting problems correct - it's often something that happens with kids at the time they move from math that is so easy they can do it in their head to math that requires keeping multi-steps straight. If that's what's up, for my kids the thing that ultimately worked was just to explain when they showed me their work or were frustrated over a test, but the key that motivated them to start writing all steps down, checking their work etc was to go through the experience of losing points due to not doing those things.
I think it's interesting that you noted your ds is gifted in math. Is there any chance that he may have some of the same issues you've noted with math work in other subjects (issues with organizing his work, inability to read his handwriting, perceived laziness etc)?If so, he *might* be dealing with something beyond a stage of needing to learn to check his math work etc. I looked back at your previous posts and noticed that you mentioned dyslexia in your family, and that your ds has a gap in profile on earlier testing between verbal and non-verbal. I don't know anything about your ds other than what you've posted here, but if he seems to have consistently and significantly stronger non-verbal vs verbal ability scores over time and you're noticing what looks like these type of problems with academic work... there's the possibility he might be a 2e kid who's issue isn't obvious simply because his high ability allows him to compensate.
Best wishes,
polarbear
