Students will explore matter that sinks or floats when submerged in water and that matter is categorized as either a sinker or a floater. Students will work actively in small, cooperative learning groups as well as gather in a whole group setting with the teacher. Students will be afforded opportunities to experience different types of matter and materials to explore whether objects sink or float. Moreover, students will understand that an object's ability to sink or float is a physical property of that object. This lesson plan was created as a result of the Girls Engaged in Math and Science, GEMS Project funded by the Malone Family Foundation.