From weight to size to motion, science is at work all around us Mass at Workintroduces young readers to a physical science concept. A high-impact design and engaging visuals help bring this important concept to life as readers learn all about mass in the real world. Aligned to Common Core Standards and correlated to state standards. Applied to STEM Concepts of Learning Principles. Sandcastle is an imprint of Abdo Publishing, a division of ABDO.