Book excerpt: Exposing children to a diverse range of literary and informational texts, the Core Concepts program helps develop important literacy and cognitive skills necessary to meet many of the Common Core State Standards. Did you know that every year hundreds of thousands of monarch butterflies migrate 2,500 miles to Mexico for the winter? It takes four generations of butterflies to make the trip, and only the fourth generation lives longer than three weeks. Follow a beautiful butterfly as she makes her journey down to Mexico! Fly, Butterfly covers the concepts Animals and Seasons.