Energy explains the ways energy is used in four different settings: home, factories, airports, and sports arenas. Each of the four books focuses on one place that energy is found and how energy is used to do work. However, the same key concepts are developed across books to help students focus on the big ideas. The theme explores the forms and sources of energy and how energy can change from one form to another. Students use the specific content and vocabulary within each book to discuss and examine these big ideas, or Key Concepts. The Theme Set Program is designed for differentiated instruction. Each Theme includes four books written at four different reading levels.