This wonderful resource is filled with practical, classroom-tested ideas for teaching mathematics with a problem-solving approach. All lessons encourage children to work cooperatively; explain their ideas; listen and question one another; and agree on solutions. Classroom vignettes describe lessons in vivid detail, and samples of actual student work are included throughout. Most lessons implement the use of manipulative materials to help children think about and reflect on mathematical ideas. Part I in this book includes six lessons that integrate ideas from different strands of the math curriculum, including algebra, measurement, probability, statistics, and logical reasoning. Part II provides two sample replacement units with a two- to three-week study focus, one on the area of a circle and the other on percents.