In this innovative book, two experienced educators present a fresh and engaging approach to mathematics learning in the middle grades with the transition from arithmetic to algebra. The authors provide a collection of balanced, multi-dimensional assessment tasks designed to evaluate students' ability to work with mathematical objects and perform mathematical actions. Assisting teachers in their efforts to put into practice the NCTM and Common Core State Standards, these assessments were carefully developed and tested to make them as revealing and adaptable as possible, suitable for incorporation into any curriculum. Teachers will appreciate the explicit and illustrative material the authors include to specifically help assess the mathematical understanding of students in grades 5-8. The text features a teachers' guide to each task, reproducible student tasks, and solutions and rubrics.