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Soap, Wood, and Water
Administration Procedures

Grade 5-8 Performance Task
Contributed by: New York State Education Department (NYSED)
NYS Alternative Assessment in Science Project (1996)


Students will measure the properties of two different types of soap and wood and calculate their densities. Then they will predict whether or not each object would float or sink in fresh or salt water.

The task assesses students' abilities to make simple observations, collect and organize data, apply mathematical concepts, and make predictions based on collected data.

This task is designed to take students approximately 10-15 minutes to complete.

Overall Task Content Area:

Earth Science

Specific Knowledge Areas:

Properties and changes of properties in matter

Performance Expectations:

  • conducting investigations
  • using equipment
  • gathering, organizing, and representing data
  • formulating conclusions from investigational data
  • applying scientific principles to develop explanations and solve new problems

National Science Education Standards:

8 A SI 1: Use appropriate tools and techniques to gather, analyze, and interpret data.
1.3 The use of tools and techniques, including mathematics, will be guided by the question asked and the investigations students design. The use of computers for the collection, summary, and display of evidence is part of this standard. Students should be able to access, gather, store, retrieve, and organize data, using hardware and software designed for these purposes.

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.

8 B PS 1: Properties and changes of properties in matter
1.1 A substance has characteristic properties, such as density, a 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.

(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:

MEAS1: Understand measurable attributes of objects and the units, systems, and processes of measurement:
Grades 6-8 j.
understand both metric and customary systems of measurement

MEAS2: Apply appropriate techniques, tools, and formulas to determine measurements:
Grades 6-8 k. select and apply techniques and tools to accurately find length, area, volume, and angle measures to appropriate levels of precision

DAP3: Develop and evaluate inferences and predictions that are based on data:
Grades 6-8 c. use observations about differences between two or more samples to make conjectures about the populations from which the samples were taken

PS2: Solve problems that arise in mathematics and in other contexts:
Grades 6-8

CNX1: Organize and consolidate their mathematical thinking through communication:
Grades 6-8

COM2: Communicate their mathematical thinking coherently and clearly to peers, teachers, and others:
Grades 6-8

REP1: Create and use representations to organize, record, and communicate mathematical ideas:
Grades 6-8

General Instructions to the Teacher:

This task is designed to take students approximately 10-15 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 "Soap, Wood, and Water":

At this station students should have:

  • 1 calculator
  • 1 balance (gm)
  • 1 metric ruler
  • 1 wood sample
  • 1 soap sample A
  • 1 soap sample B

In preparation for the activity the teacher needs:

  • soap recommendation: square white soap (i.e. Ivory), sharp cornered amber colored soap (i.e. Neutrogena)

Advance Preparation:

  • Label the blocks of soap A and B. If the labeled blocks are the same for all stations in the class label the sets 1A, 1B, 2A, 2B, etc.
  • Measure the mass and dimensions of the soap block and record the mass and volume on the teacher scoring rubric.


  • 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.


  • Use soda pop examples. Explain the density differences between Coca-Cola Classic; an Uncola diet; and an empty can (filled w/air) because of how they float.
  • To target the specific NCTM standard(s) to be measured, ask students to use customary and metric measurements.


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