6 copies of each title and reading level, 648 books total. Ladders Social Studies consists of high interest social studies topics with engaging text and visuals that align to Common Core State Standards. Through this content, students develop a clearer understanding and appreciation for the world around them. Ladders Social Studies offers titles for grades 3, 4, and 5 at three reading levels. Students whose reading levels range from 2nd grade to 6th grade will appreciate the stories and articles.