According to the CDC, approximately 9% of children ages 2-17 have been diagnosed with ADHD or ADD at some point in their lives. I can totally believe this having worked in different schools with different
age groups. I think that one of the most important things to help your child with ADHD is to acknowledge it and talk about it. A child needs to understand why they can't focus in school. Their foot won't stop moving or their pencil won't stop tapping and it's driving the rest of the class crazy, but they can't help it...and probably don't even realize that they are doing it.
My husband is probably the most ADHD person I know, and I grew up with 3 brothers with different severities of ADD and ADHD. Sure they tried the different medicines, but nothing is a cure all. It is also important to know that boys are more likely to be diagnosed than girls.
At the the end of the day, a child, as they grow older and more aware of their minds and bodies, will need to learn what helps, and what hinders their ability to focus.
It is also important that their teachers are aware of this as well and have certain interventions or services in place such as, quiet fidgets, extended time, being seated near the point of instruction, etc.
This article gives some helpful tips in identifying, and then helping your child with attention deficits.
Having someone to advocate for your child can make a world of difference. But teaching your child to advocate for themselves is even more important.