O'Connell, a classroom teacher and education consultant, and author, and SanGiovanni, a math supervisor and instructor, argue that students should understand and not just memorize math facts. They provide teachers with strategies, activities, and tips for instruction to help students master basic addition and subtraction facts while strengthening their understanding of numbers, patterns, and properties, so they have a strong foundation for more complex ideas. Facts are presented in order of complexity and are linked to those previously explored in order to build on students' prior knowledge. The book ends with a study guide for professional learning communities. The CD contains activities, templates, recording sheets, teacher tools, and reproducible forms in both English and Spanish. There is no index. Annotation ©2011 Book News, Inc., Portland, OR (booknews.com)