Now in its Fourth Edition, this renowned text continues to teach effective calculation methods to nurses. With a systematic, organized approach that progresses from simple to complex problems. Features include self-tests at the end of each new area, with answers provided, and proficiency tests are featured at the end of each chapter. The core of the book covers dosage calculation while ending chapters cover information basic to drug administration, such as legal and ethical considerations and pharmacokinetics. New features to this edition include full-color illustrations; an accompanying interactive CD-ROM with practice problems; enhanced content on the ratio-proportion method; and, critical thinking case studies.