Is it possible to double major in Math and Computer Science. I’d like to major in math with a degree from the CAS, and major in computer science with a degree from SEAS.
This is definitely possible. You do have to apply to the school outside of your home school (the one you were originally admitted into), which is not guaranteed, but if you perform well in math/physics/computer science courses and take the necessary courses (at the second part of this page http://www.seas.upenn.edu/undergraduate/degrees/dual-degrees.php), it should not be too much of a problem. The one tricky part of doing a dual degree (a double major would mean you only get one degree) is fulfilling all of the general requirements from both the College and Engineering, though many of them can overlap. A lot of people avoid taking both sets of requirements by double majoring and only getting one degree. However, with careful planning it should be very possible to do this.