So I spent a little time yesterday with the College Board's ACCUPLACER iPhone study app ($1.99). It has three math sections: Arithmetic, Elementary Algebra, and College Level Math.
You can check out some sample questions here.
In lieu of a longer post, let's just say these sections are all straightforward -- much moreso than the NECAP -- and map more closely to math as exercised in math class. Each section looks pretty much as you'd expect.
If this can be used as an alternate assessment in the RI graduation requirement, I'd recommend looking into it more closely, particularly the exact score required. But it is probably a better choice for getting over the hump, especially since there are more prep resources available.