Confused about SAT IIs

<p>I know SAT II's are basically required for all ivies and ivy-caliber schools. I have decided to take the Chemistry SAT in May, as I'm taking AP Chem and love it.</p>

<p>However, I'm not sure how many more I should take (I know one more is required). I figure at least 3. Is this fine?</p>

<p>Also, I'm not sure which classes I should take them in. US, Math II or Writing? I'm strongest in US and Writing, but I need to show colleges I'm strong in math to offset my 660 (I'm retaking this sat I score, but I'm using this as if it were final for now). I have the chance to prove this with my AP Calculus score, but I'm not counting on a 5!</p>

<p>Most ivies require 2, Princeton and Harvard require 3.
I would say US and Math II as Writing has been incorporated into the SAT I.</p>