Mighty Express: Calling All Trains! A STEM Gear Sound Book is an exciting and educational book that combines the fun of trains with STEM learning. Written by PI Kids, this book features interactive sound buttons that bring the story to life. With its mixed media format, this book is perfect for young readers who love trains and want to explore the world of STEM. Join the Mighty Express train crew on their adventures as they solve problems and learn important STEM concepts. This book is a great way to engage children in reading and learning while having fun with trains.