8th Grade Performance Task
Contributed by: New York State Alternative Assessment in Science
Project (NYSED)
1996 Administration
Description:
Students determine the mass, volume and density of a sinker, given
simple tools to work with. They then apply their understanding to
an additional situation. The task assesses students' abilities to
make simple observations, measure volume using a graduated cylinder,
measure mass using a balance, make generalized inferences from their
observations, and apply their understanding to an additional situation.
This task is designed to take students approximately 1015 minutes
to complete.
Overall Task Content Area:
 Physical Science
Specific Knowledge Areas:

Performance Expectations:
 conducting investigations
 using equipment
 gathering, organizing, and representing data
 applying scientific principles to develop explanations and solve
new problems
National Science Education Standards:
8 B PS 1: Properties and changes of properties
in matter: Grades 58
1.1 A substance has characteristic properties, such as density,
boiling point, and solubility, all of which are independent of the
amount of the sample. A mixture of substances often can be separated
into the original substances using one or more of the characteristic
properties.
8 A SI 1: Abilities necessary to do scientific inquiry: Grades
58
1.4 Develop descriptions, explanations, predictions, and
models using evidence. Students should base their explanation on
what they observed, and as they develop cognitive skills, they should
be able to differentiate explanation from description — providing
causes for effects and establishing relationships based on evidence
and logical argument. This standards requires a subject knowledge
base so the students can effectively conduct investigations, because
developing explanations establishes connections between the content
of science and the contexts within which students develop new knowledge.
1.8 Use mathematics in all aspects of scientific inquiry.
Mathematics is essential to asking and answering questions about
the natural world. Mathematics can be used to ask questions; to
gather, organize, and present data; and to structure convincing
explanations.
(Use the "hot" link on the PALS home page
to check the full text of related National Science Education Standards,
if desired.)
National Council of Teachers of Mathematics:
Number and Operations (NO2): Understand meanings of operations
and how they relate to one another.
Number and Operations (NO1): Understand numbers, ways
of representing numbers, relationships among numbers, and number
systems.
Measurement (MEAS2): Apply appropriate techniques, tools,
and formulas to determine measurements. a.
Problem Solving (PS2): Solve problems that arise in mathematics
and in other contexts.
Connections (CNX3): Recognize and use connections among
mathematical ideas.
General Instructions to the Teacher:
This task is designed to take students approximately 1015 minutes
to complete.
Students will be working individually during this exercise.
Students should be ready to work as soon as the period begins.
The materials should be set out at each lab station, if possible.
A central supply area, if needed, should be easily accessible. All
supplies should be clearly labeled.
Materials for "Density of a Sinker":
At this station students should have:
 spring scale or balance
 100 ml beaker with water
 modeling clay
 calculator
 graduated cylinder (at least 50 ml)
 1 oz lead sinker
 string
Advance Preparation:
 Put a small piece of modeling clay in the bottom of the graduated
cylinder. This will pad the graduate in case the student drops
the sinker into the graduate.
 Tie a string to the lead sinker so that the students can gently
lower the sinker into the graduated cylinder. This will also help
them to get the sinker out of the graduate.
Safety:
 Caution the students against dropping the sinker into the graduated
cylinder.
 If any glassware breaks, instruct the students NOT to attempt
to clean it up themselves but to inform the instructor immediately.
 Be careful.
 Teachers and students should always exercise appropriate safety
precautions and utilize appropriate laboratory safety procedures
and equipment when working on science performance tasks.
Extensions/modifications:
 Grade 8 task collection  Unknown Liquids
 Earth Science Task collection  Density of a Mineral
