If you are good at math and love design as well, use both aspects of your nature and pursue web development. The coding can appeal to the math side of your brain and the design elements can appeal to your creativity. Plus, students get wicked good deals on Adobe products
In reality though, it's up to you. You have to do what really engages you and matches your passions and sometimes it takes a little bit to figure that out. You may find you change majors a time or two - or 3 like me lol.