Book excerpt: Play is serious business. Whether it's reenacting a favorite book (comprehension and close reading), negotiating the rules for a game (speaking and listening), or collaborating over building blocks (college and career readiness and STEM), Kristi Mraz, Alison Porcelli, and Cheryl Tyler see every day how play helps students reach standards and goals in ways that in-their-seat instruction alone can't do. And not just during playtimes. "We believe there is play in work and work in play," they write. "It helps to have practical ways to carry that mindset into all aspects of the curriculum." In Purposeful Play, they share ways to: optimize and balance different types of play to deepen regular classroom learning teach into play to foster social-emotional skills and a growth mindset bring the impact of play into all your lessons across the day. "We believe that play is one type of environment where children can be rigorous in their learning," Kristi, Alison, and Cheryl write. So they provide a host of lessons, suggestions for classroom setups, helpful tools and charts, curriculum connections, teaching points, and teaching language to help you foster mature play that makes every moment in your classroom instructional. Play doesn't only happen when work is over. Children show us time and time again that play is the way they work. In Purposeful Play, you'll find research-driven methods for making play an engine for rigorous learning in your classroom.