It would seem to me that unless you have a serious hook (like being recruited to play a sport), applying ED will not get you in unless you can get the math score on your SAT way up above 600. Really, the 25th percentile is 630. I think you need to get it up a LOT closer 700, and getting it up above 710 (the 75th percentile) wouldn't hurt at all. Why would they take someone ED with a really low score on any part of the SAT if they could potentially fill that spot with someone with higher scores later in regular decision? I think ED is not a way to skate in with low scores, I think it is a way for someone with great scores to get in early compared to later when they are swimming with the sharks in Regular Decision and competing with a much bigger pool of strong applicants. Have you considered taking the ACT or the Math SAT II? My daughter did better on the math component of the SAT Subject test AND the ACT exam than she did on the math component of the regular SAT exam. She took the SAT exam twice and the best she scored was a 710, but she scored a 730 on the SAT Math Level II subject test, and a perfect 36 out of 36 on the Math portion of the ACT. I think you should try something different to demonstrate a strong math background before applying ED, even if it is retaking the SAT again. If you can't get your scores up with the SAT exam, do a subject test or an ACT exam.