Whole Numbers and Integers

A patient’s fluid balance chart tells a mathematical story before it tells a medical one. When an intravenous line delivers 1,200 milliliters of saline, and the patient subsequently voids 1,500 milliliters, the resulting net balance is not simply a difference; it is a negative value representing a physiological deficit. The charting of this minus-300 milliliter state is the fundamental language of integers at work. In nursing and allied health professions, mastering basic numerical operations is not a mere academic hurdle to clear for the HESI A2 exam—it is the bedrock of patient safety, medication administration, and metabolic monitoring. We must understand exactly how numbers behave when they cross the threshold of zero.