Ensure children's deep understanding of addition and subtraction in ways that enable long-term growth-with child-centered instructional strategies, powerful and engaging learning materials, and revealing assessment tools. Common Core aligned. Based on his belief that children are mathematically curious by nature, author Greg Nelson presents a variety of tools classroom teachers can use to give students access to the deep structure of numbers, carefully scaffold their inquiry, and help them excel in math. The goal of this resource is to guide teachers as they feed children's innate mathematical curiosity and scaffold their insights without taking ownership of the process away from them. To that end the author provides effective tools of instruction and assessment, with clear guidelines for teaching a different way. In order to help ensure that mathematics learning is a learner-centered process, rather than one forced by adult-sequenced series of rules and facts, the book focuses on seeding the environment with mathematically intriguing tasks just beyond children's current level of mastery and then giving them the freedom to use that environment in personally meaningful ways. In doing so the book provides a host of suitable materials and activities that encourage self-educating, and suggests how adults can maximize their impact on the child's learning through careful observation and strategic intervention.