Wood Identification Based on Density

Keywords: mass, volume, density, characteristic properties; Lesson Plan Grade Level: eighth; Setting: classroom

Goals for the Lesson

  • Students will measure length, width and height in centimeters
  • Students will identify regular versus irregular shaped solids
  • Students will calculate volume by multiplying length x width x height
  • Students will calculate mass in grams
  • Students will calculate density in grams per cubic centimeter

Materials Needed

  • metric rulers
  • four beam balance
  • wood samples of five different species
  • calculators
  • data chart

State Standards Addressed: Science and Technology; Inquiry and Design (3.2.10)

Teaching Model: Traditional

Subjects Covered: biology, mathematics

Topics: botany, density, linear measurement, mass measurement

Preparation

  1. All wood species will be cut into regular shaped pieces.
  2. All species will be kiln dried to the same moisture content
  3. All students will practice measuring in grams.
  4. All students will practice measuring in centimeters.
  5. All students will practice the density formula (density = mass/volume)
  6. All students will make data sheets to record mass, length, width, height, volume, density,
  7. sample number.
  8. All blocks of the same species should have the same number marked on the block

Activity

  1. Review the formulas needed to calculate volume and density.
  2. Place students in groups on two or three.
  3. Give each group calculators, metric rulers, balances, and five different wood samples.
  4. Have each group record length, width and height for each sample to the nearest 0.1 centimeter.
  5. Have each group mass each sample to the nearest 0.01 gram and record.
  6. Have the students calculate volume in cubic centimeters and record.
  7. Each group can now calculate density by using the density formula and record in grams per cubic centimeter.

Assessment

Have students match their densities to a handout with seven or eight different wood species with their densities attached. Collect data sheets and check densities.

Conclusion

Discuss the following:

  • Size does not affect density.
  • Density can be used to identify many things.
  • How does density affect the use of different species?
  • Which errors could influence density calculations?

Author

Alex Fox, Mifflin County School District