In this Hour of Code, students learn about how they can use computer science to help solve one of the biggest problems facing our world today: litter and waste. Students start by exploring real world examples of how engineers are using computer programming to reduce the amount of litter in their community. Then, they choose between two programming adventures: Clean Up with Karel or Web Design for a Litter-Free Community. In Clean Up with Karel, students learn the basics of programming in Python by giving commands to Karel. In Web Design for a Litter-Free Community, students learn the basics of HTML by creating their own webpage.