I just wanted to mention that omegas really work for some kids.  For my kids, they all appear to be adhd.  I find that fish oil really calms them down, and as a side effect, their vision has improved (they all wear glasses), and they get less colds.  I give my kids liquid fish oil and/or cod liver oil.  For some reason, they can't or won't swallow pills, they'd rather take the oil.  I give them juice right away, as long as they don't smell it, and have juice right after, they don't really taste it.  Also, I give them more like megadoses, 3,000-5,000 mg.  I searched these info online, and started them on those high doses.  It took about a month for me to notice the difference, and oh boy, is there a difference!  A couple of times I had to stop for a few weeks, and they get so impossible, I begin to feel like I'm losing my mind!  Within a few weeks of giving the oil again, I notice how much better they get.  
The only side effect I see is that its an extra 400 or so calories a day, but their vision has improved, and their health is much better.  The oldest used to be on adhd meds, and I was able to take him off them.  I never gave the youngest ones, and hopefully won't have to in the future.  Anyway, I hope it really works for you.  My kids take the Vitamin Shoppe brand (I used to buy a really expensive brand, and was speding $60 a month on it, but one day tried the vitamin shoppe one, and the kids say it tastes the same, now I spend about $18 a month).
The gummies for kids, we tried them, but they would have to eat to many to get a high dosage, so it was way too expensive.  Eventually, I hope they will swallow pills, then it will be easy to buy a large amount on sale.  
Well, if you feel the gummies work, fine, but if you start noticing a plateu, try to se if you can get your dc to swallow the oil.  Also, the gum chewing is a great idea!  I read a study was done that shows it helps students do better in school.
http://children.webmd.com/news/20090423/math-plus-chewing-gum-equals-better-grades