Blackcat,
i'm gonna check out that link for milestones but the first few questions you asked - he speaks in full sentences and asks and answers questions. he's less likely to engage though and isn't like to initiate very much conversation and he sounds babyish when he talks. its hard to explain. i'm looking into a possibility of getting him evaluated to see of there is a 2E component - now, after reading through all your guy's responses. I worry though that taking him in for an email is ASKING for a diagnosis. honestly, really didn't think so but now I'm wondering.

i want to understand what you were saying about the kids who are mathematically gifted though and i don't know if i do yet. so, he might be advanced in math but not be a gifted child? if theres a difference i thinks it important information for us to have because we don't want to spin our wheel headed in the wrong direction. to our way of thinking - because he's doing 5 and some 6th grade math - he MUST be gifted, but if that isn't the case or at least potentially not the case then it would kind of clear some things up for us. we've been very confused about what he can do Vs. how the tested he did last year went.

there is other components though - the reading, and language arts (on paper at least) he's advanced. reading about 2nd grade or maybe somewhere between 2nd and 3rd (he can read to learn and read instructions and follow them correctly) - hand writing and language arts, he works from 1st grade material but we do some stuff that i think qualifies as second grade. like alphabetizing, nouns, verbs stuff like that.

its an odd juxtaposition between who you see when you first meet him and what he's able to do with books, paper and pencils.

heres some examples of the math he'll do this week.
adding, subtracting, multiplying and dividing fractions with borrowing and mixed numbers
subtraction with multiple borrows like...
4000
-3892
3 digit x 3 digit multiplication with carrying
long division with decimals
he does big multiplication his head like 8 x 320, you can ask him how many seconds are in 12 minutes or something like that.
he does minor pre pre algebra like 5y-3=12 y=
area and perimeter
order of operation
roman numeral into the tens of thousands
prime vs composites and prime factors (loves prime numbers, don't ask me why, i don't get them at all)

bunches and bunches, i could keep listing stuff but i think thats probably a good grouping of examples. He's extremely fixated on math and numbers and value, it takes on a very wide and also in-depth scope.