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“A bright story that demonstrates the ways we use math in everyday life. César wants to borrow one of his little sister’s crayons, but she won’t let him touch them. Only Gabi can give him the crayon he wants, if only she can figure out what cerulean is. Thus ensues a clever process of elimination, with territorial Gabi facing off against the increasingly frustrated ­César. It’s a window into an all-too-familiar sibling ­dynamic, a slice of life many readers can identify with. Along with the subtle math hints, both Gabi and César sprinkle in Spanish words. Further explanation can be found in an author’s note, along with interactive tips for adults, showing how to encourage the math connections during reading.”

—School Library Journal

César’s Cerulean Surprise

Written by Jenny Lacika
Illustrated by Laura Sandoval Herrera
Published by Charlesbridge

Celebrate diversity, math, and the power of storytelling!

A math picture book series for preschoolers and kindergarteners with relatable stories that reflect little kids’ everyday experience.

César wants to borrow his little sister Gabi’s brand-new cerulean crayon. She doesn’t know what color that is, though, and she won’t let him show her! Instead, she asks him yes-no questions to rule out crayons. It’s like a game of 20 Questions—fun for Gabi and frustrating for César!

A playful exploration of logic featuring Chicanx (Mexican American) characters and Spanish color 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.

Primary ISBN: 9781623544393
Publication Date: October 2025
Available As: Hardcover, Paperback, eBook
Picture Book, Age 03 or older

Community Represented:

Themes: , , , , , , , , , ,

Setting: United States

Character's Place in the Immigration Journey: Unknown Arrival

Book Creator(s) Connection to the Community Represented: Own Voices/Lived Experience

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Engagement Projects & Resources:

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Engagement Materials:

Story Telling Math Activity Guide

Source: Charlesbridge