Things That Float and Things That Don’t

Adler shows his customary skill for explicating mathematical concepts in this smart exploration of floatation and density. Several experiments allow for a hands-on approach: Adler suggests filling a sink with water and testing whether different objects float, as well as using modeling clay to demonstrate how shape is as important a factor as density. Raff’s pastel palette and cheerful characters keep the mood light and pair well with Adler’s explanations, which are clear without being dauntingly technical. Along with Lynne Berry and Matthew Cordell’s What Floats in a Moat? (reviewed Apr. 29), readers will be well-prepared when it comes to displacement and density this fall. Ages 4–7. Author’s agent: Jodi Reamer, Writers House. (Sept.)