specific intelligences could be defined as their ability to "process" types of information, hence mathematical intelligence could analyze and synthesize mathematical ideas (synthetic a priori judgements would be the technical term), quickly. "discrimination" would be the analytic part of that. other kinds of intelligence would likewise discriminate according to their objective, like emotions, spacial relations, linguistics, etc. numbers are very exact, their granularity is almost limitless but that makes discrimination easier in some sense because we can use methods to positively determine their status and do not need rely on pure "intelligence" in the same way, say, as basketball player must. this is probably how EIE can get great at math, but he's probably not going to win top mathlete when it comes down to calculating in real time, where its more like a basketball game
of course over a long enough time period EIE might be able to come up with something completely novel in mathematics, which could make far more of a mark then being a human calculator will, so I suppose it relies on criterion for judgement as well. if you really think about it the whole concept of specific intelligences is highly circular in that sense. there's as many types as goals we can posit, but really only one underlying factor--the ability to, all other things being equal (which they never are) do something faster.. roughly that would correspond to fluid intelligence (the all other factors being equal). but since nothing is ever totally equal crystallized intelligence becomes a meaningful measure and factor
in that sense the idea of there being multiple intelligences doesn't seem to be strictly speaking supported, except as a heuristic to talk in terms of "being fast at x domain"