The students were asked to describe how to find the density of different
substances.
| This sample of student work was produced under the following
conditions: |
| alone |
in a group |
| in class |
as homework |
| with teacher feedback |
with peer feedback |
| timed |
opportunity for revision |
| 
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b Physical Sciences Concepts:
The student produces evidence that demonstrates
understanding of the structure and properties of matter….
 Here, and throughout
the work, the students show their understanding of density.
e Scientific Thinking: The
student identifies problems, proposes…solutions….
 The students point
out that customary technique for finding the volume of an irregular
solid, water displacement, which they used for the rock, will not
work for solids with densities less than water. They propose a reasonable
solution to that problem by suggesting that the less dense solid be
attached to a very dense solid, such as iron, so that the combined
density would be greater than water. Thus, the combined solid would
sink.
a Scientific Tools and Technologies:
The student uses technology and tools…to
observe and measure objects…directly and indirectly…with
appropriate consideration of accuracy and precision.
Attention to accuracy is evident in the care taken with significant
digits.
 
Attention to precision is evident in the comments about holding and
reading a ruler and reading the level of the graduate cylinder.
a Scientific Communication:
The student represents data and results
in multiple ways, such as…tables, and graphs;…diagrams….
The table is well
designed to show which values were measured and which were calculated.
e Scientific Communication: The
student communicates in a form suited to the purpose, such as by writing
instructions that others can follow….
Throughout the work, especially at 
and , the instructions
are very straightforward and easy to follow. |
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