<p>If Illinois, is it easy to change majors from Math to Comp Sci? Besides, how prestigious is their Math major?</p>
<p>Not so easy. Math is in the Arts & Sciences college, where there is also a CS minor that you can add to a math major. However, to major in CS, you would need to transfer to the College of Engineering. To transfer, which is usually done after second year, you need to (a) have taken required courses that freshman and sophomore CS majors take (which includes chemistry and calculus based physics and certain CS courses), and (b) have a minimum GPA even to apply (it changes but usually in the 3.2 range) and usually you even need higher than the minimum to actually have the engineering college approve the transfer. In other words, if you take the required courses and get a high GPA, your chances of being able to transfer are good, but getting a high GPA is not easy. The math major is fine but, like math majors anywhere, your employment opportunities will not be as good as a CS major.</p>