AS TEACHERS OF MIDDLE GRADES, WE RECOGNIZE THAT MEASUREMENT IS an integral part of the curriculum throughout each year. Middle-grades students come to the mathematics classroom with formal and informal experiences in measurement from prior instruction and from activities in their everyday lives. Building on this foundation, we want to provide a curriculum in which students develop an understanding of the relationships among measurable attributes of an object. We want students to learn to apply appropriate techniques, tools, and formulas to make measurements and obtain derived quantities.