I am from family with ADHD. both my parents have it. I have it too.

Basically our mind is like a ballroom party, many thoughts going on at once. We end up doing one thing and thinking of other thing, very difficult to focus.

I always advise against doing "test" on your children. You do it only when it's a part of process, like u need the certification for your next course of action. You need to ask yourself this, what do u want out of the test? To satisfy your curiousity? Or u need the documents to apply for medications, to treat your kid.

ADHD is not a disease, So no cure. You can only learn to live with it. For example. We learn stuff differently, most kids can outright memorize and regurgitate the whole topic. ADHD definitely couldnt, they have their own way of learning, for me i need to learn stuff by forming a coherent and logical story. If u tell me apple falls because of gravity, i would not be able to remember this gravity stuff. Unless u go through the long ass story, like how gravity forms, why is it important to learn this, what's the implication of this stuff. etc etc. In short i can never memorize shit just because i need to, i wont be able to remember it unless i understand it. This is just a small preview of how different our mind works.

I forever be grateful my parents knew the chinese school system is not right and sent me to SK instead. ADHD ppl go chinese ed is insanely difficult, their way of teaching will kill their interest in learning completely.