Description: One of a series of documents describing the progression of a topic across several grade levels, informed both by research on children's development and by the structure of mathematics. Students often initially hold undifferentiated views of measurable attributes, saying that one object is "bigger" than another whether it is longer, or greater in area, or greater in volume, and so forth. For example, two students might both claim their block building is "the biggest." Conversations about how they are comparing-one building may be taller (greater in length) and another may have a larger base (greater in area)-help students learn to discriminate and name these measureable attributes.*Teacher Advisor is 100% free.