Switched-On Schoolhouse 3rd Grade History & Geography - Explore the United States as never before with the fully updated SOS 3rd Grade History and Geography. With an easy-to-follow, student-directed learning format, this course lets students set their own pace while studying mountains, rivers, fields, plants, animals, and people in each U.S. region. Plus, map reading skills and age-appropriate vocabulary add to the understanding of what makes each area in our country unique.