I see you have another thread about Georgia Tech / Purdue / UIUC, in which you mentioned IE and ECE / CE majors?
Are you thinking that you might be more interested in math / applied math, rather than these majors? Or are you thinking about applying for math as a backdoor to later switch into an engineering major?
Edited to add: here are the other two threads with more background info if it helps people respond to this poster,