Be a 4-H Scientist! Materials in a Green, Clean World is an inquiry-based science curriculum focusing on concepts of materials; plastics; reuse, recycle, and reduce; and the work of scientists and engineers. It is designed to build foundational skills of science and engineering: observation, asking questions, sorting and classifying, and communicating. The curriculum contains six learning modules intended for delivery in out-of-school time facilitated by an educator (trained volunteers or program staff). Most modules also include a “Science At Home” activity which parents/other adults and children can do at home.