S1 was a math major – wanted math to support his interests in theoretical CS. In the mid-Atlantic/Midwest, looked at Michigan, Chicago, UMD-CP (our flagship), MIT. Had stats and national awards to support the application. He went to a STEM program in HS and Wisconsin was a popular and excellent school for math. S had considered it for a time.
Like NJCornellMom, my son visited classes (would contact a prof prior) and sat in on honors analysis-type courses because that’s where he was going to be when he started college. NEVER had a problem, and almost every prof chatted with him afterwards. This was ten years ago now, so that landscape may have changed.
Drexel is generous with scholarship $$. UMD is as well – it’s great for math/CS, has a good hiring record with major computer companies (Sergei Brin went to UMD for UG) and if you get a Banneker/Key, it’s a great scholarship. It has gotten much more competitive. UMD is generous with AP credits and placement testing, so many of the top students we know who attended did two majors and graduated in four with ease. There is a good contingent of S’s friends who took the free ride and are now at MIT/Duke/Oxbridge/Harvard/Caltech/Columbia, etc. for grad school. Most of them turned down similar admits for UG.
W&M, UVA and UNC-CH are outstanding schools, but hard to get into from OOS.