My DS10s teacher wants them show their work. You can do it anyway you want as long as the answer is right. If you don't show your work and get the wrong answer it is wrong. If you showed your work you might get a bonus if you are anywhere in the ball park. If you show your work in the way the teacher has explained it you might get a bonus+1.
They are working on problems lately that make you work backwards. I believe your son might have an edge with his verbalized solutions.
I have no idea if you should be worried or not. I do know the kids love to work on there verbal explanations with each other.
