Book excerpt: Accurately calculating medication dosages is a critical element in pharmaceutical care that directly affects optimal patient outcomes. Unfortunately, medication dosage errors happen in pharmacies, in hospitals, or even at home or in homecare settings everyday. In extreme cases, even minor dosage errors can have dire consequences. Careful calculations are essential to providing optimal medical and pharmaceutical care. Essential Math and Calculations for Pharmacy Technicians fills the need for a basic reference that students and professionals can use to help them understand and perform accurate calculations. Organized in a natural progression from the basic to the complex, the book includes: Roman and Arabic Numerals Fractions and decimals Ratios, proportions, and percentages Systems of measurement including household conversions Interpretation of medication orders Isotonicity, pH, buffers, and reconstitutions Intravenous flow rates Insulin and Heparin products Pediatric dosage Business math Packed with numerous solved examples and practice problems, the book presents the math in a step-by-step style that allows readers to quickly grasp concepts. The authors explain the fundamentals simply and clearly and include ample practice problems that help readers become proficient. The focus on critical thinking, real-life problem scenarios, and the self-test format make Essential Math and Calculations for Pharmacy Technicians an indispensable learning tool.