If you know ahead of time that they will require college ruled paper (or graphing paper for your math class), then it should be safe to say that you will need some in your binder. However, don’t throw your wide-ruled paper out. Use it as scratch paper for your math class, for doodling, writing notes that do not need to be checked or collecting, or writing letters to friends. You could keep a small section of “scratch paper” and a thicker selection of college ruled paper for your courses.