Knowledge and Skills Statement
Matter and energy. The student knows that matter has measurable physical properties that determine how matter is identified, classified, changed, and used.
Further Explanation
In everyday use, mass and weight are sometimes incorrectly used interchangeably. Students in grade 3 are expected to measure mass, however they are not expected to understand the role gravity plays in differentiating between mass and weight. In science, mass is always measured in metric units (kilograms). Experiences in science with scales and balances will help support students' development of understanding mass versus weight, while in mathematics students will understand units of measurement as customary and metric.
As an educator, it is important to understand the differences between mass and weight.
Weight is measured on a scale and accounts for the downward force of gravity.
When measuring mass, an object is placed on one side of a balance and counterweights are placed on the opposite side of the balance. This use of a counterbalance means that the measurement taken is consistent regardless of the force of gravity in an environment. In other words, while the weight of an object measured on a scale is lighter on the Moon than it is on Earth, the mass of the object measured with a balance would be the same.
Supporting Information
Research
Palmeri, Amy, Amanda Cole, Sarah DeLisle, Stacey Erickson, and Jennifer Janes. 2008. “What’s the Matter With Teaching Children About Matter?” Science and Children 46, no. 4 (December 2008): 20–23. http://www.jstor.org/stable/43175007.
Summary: In “What’s the Matter With Teaching Children About Matter?”, common misconceptions children may have about matter are explained, and instructional strategies to bridge that gap are provided. Children naturally use physical properties to describe matter, using words like "hard" and "thick" and describing odor. Students use their observations to classify matter.