I have no idea what is meant by "Scottish higher level", I'm afraid. If you're a freshman at the university level, then you're likely studying either Pre-Calculus, Calculus, or Differential Equations. For Pre-Calculus, I'd recommend Morris Kline's Mathematics for the Nonmathematician. For Calculus, I'd recommend the same author's Calculus: An Intuitive and Physical Approach. For Differential Equations, I'd recommend Tenenbaum and Pollard's Ordinary Differential Equations. All three are Dover books, and therefore quite inexpensive - and yet the quality is excellent.