Ladders Differentiated Readers Are A Family Of Three Distinct Programs Focusing On Developing Reading Comprehension Skills In Support Of The Common Core State Standards. The Original Ladders Common Core Readers Meet The Challenges Faced By The Diverse Reading Needs Of The Typical Classroom. Each Ladders Common Core Title Reaches Every Student Through Multiple Reading Levels, While Focusing On The Exact Same Quality Content, Vocabulary, And Visuals From National Geographic.