The Solution CDs contain a multimedia step-by-step explanation to every single one of the almost 3,000 homework problems in the sold-separately textbook. Whether you wish students to proceed more independently, or simply want to give him or her access to a library of quality explanations to supplement and reinforce understanding, this is the tool you need. The Lecture & Practice CDs contain 10-15 minute lectures for every lesson in the print textbook. Multimedia step-by-step explanations to the 5 practice problems which accompany each lesson are also included. Ideal for students who benefit from listening and watching in addition to reading. Over 120 hours of instruction.