Again, Essie?

Rafael has a problem: his little sister, Essie, keeps getting into his toys. To keep her away, he collects everyday objects from around the house and sets about raising a barrier. Will his wall hold up? And what is Essie after, anyway?

The story is a playful look at physical space and geometry, and its characters are Chicanx (Mexican American). A glossary of Spanish words is included.

The book is part of the Storytelling Math series, which shows children using math in the course of their everyday play, building, and exploring. Its stories are paired with hands-on activities that help kids and the grown-ups who read with them explore math together in daily life. The series was developed with math experts at TERC, a STEM education nonprofit, under a grant from the Heising-Simons Foundation.