Rafael wants to protect his toys from his little sister, Essie. Gathering materials from around the house, he builds a wall tall enough and wide enough to keep her out. But will it be strong enough? And what does Essie really want? A playful exploration of physical space and geometry, featuring Chicanx (Mexican American) characters and a glossary of Spanish words.

Storytelling Math celebrates children using math in their daily adventures as they play, build, and discover the world around them. Joyful stories and hands-on activities make it easy for kids and their grown-ups to explore everyday math together. Developed in collaboration with math experts at STEM education nonprofit TERC, under a grant from the Heising-Simons Foundation.