Grade 2 - Shape and Space
Standard 2.SS.2 - Compare different objects and determine which is heavier or lighter.
Included Skills: Measurement, Comparison
Demonstrate understanding of non-standard units for measurement of mass by: • describing the choice and appropriate use of non-standard units • estimating • measuring • comparing and analyzing measurements. • Defend the choice of a non-standard unit for measuring a mass in a situation relevant to one's self, family, or community. • Estimate the mass of a personally relevant object using one's own choice of standard unit. • Identify a non-standard unit for measuring mass that would not be a good choice in a particular situation and explain the reasoning (e.g., to measure the mass of a desk, it would not make sense to use an eraser as the standard unit because a desk has so much more mass than an eraser and so it would take too many erasers, or to measure the mass of a library book using the standard unit of a student in the class because the student already has a greater mass than the book). • Compare estimates of the mass of the same object determined using different standard units and provide reasons for different values being stated for the measurements. • Explain why the same non-standard unit should be used to determine mass measurements that are to be compared. • Compare and order sets of related objects according to mass measurements and explain the reasoning.