Population Density is an activity to engage students in working with the population density formula. This activity provides a unique way to group students by working with the clock and making appointments with other students which forms five different groups for each student. Every time on the clock has a set of problems to calculate population density. The problems start out easy and become more difficult. The outcome of this activity gives students practice using word problems to calculate any part of the formula for population density. This activity includes teacher instructions, student activity sheets (clock and problems) and an answer key.