Each book offers real-world science connections through an iScience puzzle and discovery activity. Through exploration and application, readers strengthen their critical thinking skills while making history and career connections. The series includes three levels of difficulty, offering progressively more challenging text and problem-solving activities. It aligns with grade-appropriate reading levels and Next Generation Science Standards. This complete set includes all 30 readers, covering a wide range of topics and learning opportunities.Details:Multicolor (varied cover designs with educational illustrations)It aligns with grade-appropriate reading levelsThis complete set includes all 30 readersAges 8 and up