I think it is also a maturity level of tackling the task. We experienced this with DD and CTY. She is high energy and she likes to do things fast. Even when I told her she needs to slow down and do the "work". She would make silly mistakes like adding two numbers to get 67,then writing 67 tens because she just rushed. even though we reviewed and went over the material,
Two seconds later, she just took shortcuts and had the answer but did it wrong. She even wrote 0-50=50 when she did much advanced math correct. She knows the answer, who knows what goes on in their heads at this age. Distraction?
Some kids are focused. The problem is that I know I was really unfocused too. Yet, the math totally came together for me later, so I advanced many years. So I am a great believer in the VS adjustment. That in the early years, the highly VS learner just has distraction issues which causes silly mistakes.
But there are cognitive skills that blow the mind when they just produce answers. I think it all comes together later. The brain is still developing...
Ren