This document discusses population density and distribution. It defines population density as the number of people per unit of land area, calculated as total population divided by total land area. Physiologic population density is defined as the number of people per unit of arable or cultivated land. Factors that can impact population density include indicators of development that may increase or decrease density. Population distribution refers to the pattern of where people live within a physical region, and is impacted by various social and environmental factors. The document provides worksheets for students to complete calculations of population densities and distributions with partners using textbook readings and maps.