In this optional lesson, students use maps to compare the forested area of a location at two different times. They begin by remembering strategies to calculate the area of a polygon. They then are presented with two maps of the same location, before and after development. Students compare the forested areas in each map and discuss the deforestation and reforestation in the area. Students make sense of the problem by making a plan for how to find the area of the forested land (MP1). They construct and critique arguments when comparing plans and solutions (MP3). This lesson relies on skills developed in Unit 1 but can be approached in more ways if taught after later units.

This lesson can be used anytime after Unit 2 is completed.