In these PBS Mathline activities students practice operations with whole numbers, decimals, and percents as they solve word problems concerning garbage and paper usage. The problems in the first two activities, "What We Do Adds Up " and "A Little Recycling Goes A Long Way," encourage grade 4-8 learners to consider the impact of our actions on the world. The resource includes an Ecosystem Ecologist's discussion of the role of math in her career and a link to Recycle City, an EPA website on sustainable practices.