Sounds like you guys are seeing what I am: if he's bright, per the CogAT, but he isn't testing well on content areas, per the ITBS, then it kind of seems to indicate that he is *particularly* in need of some special educational focus?
Not necessarily. It could mean he just had a bad test day, it could mean he hasn't been taught the material, it could mean his score was artificially low because the test was timed and he's not a rapid-fire-fast kid with calculations, or it could mean he's just not really that interested in math and hasn't moved ahead in achievement by leaps and bounds. *IF* you are seeing a discrepancy in test scores (achievement vs ability) *and* issues with his academic performance or other things going on that appear to be challenges either inside or outside of school - then I'd look into the possibility of a learning disability or some other type of challenge.
I just don't know if I should act on this information, or if someone would offer me a little reality check slap and a reminder that if his scores didn't qualify him for gifted education, it's because he doesn't have the pressing need for differentiation that a HG+ child would!
What grade is he in? Are the gifted services something he would benefit from?
I have no knowledge of your school district, but in some districts, it's possible to appeal this type of decision if you have independent testing that can be used in place of the CogAT or ITBS scores. I'm also not sure what the SIGS is, but how did he score on that? Is it a rating system? Does his teacher believe he should be in the gifted program? A teacher's advocacy also goes a long way in our district - as well as parents who advocate for their children. It definitely helps to have data to back up your advocacy though!
Best wishes,
polarbear