Density, Weight & Mass Lesson Plan: Candy Bar Lab

Submitted by: Robert Miller

Grade Levels: 3-5, 6-8, 9-12

In this lesson plan, which is adaptable for grades 3-12, students use BrainPOP resources to compare and contrast the basic properties of solids such as mass, volume, color, and texture. Students will differentiate between weight and mass, and explore and describe the densities of various materials through measurement of their masses and volumes.

Lesson Plan Common Core State Standards Alignments

Students will:

  1. Compare and contrast the basic properties of solids such as mass, volume, color, and texture
  2. Differentiate between weight and mass recognizing that weight is the amount of gravitational pull on an object and is distinct from, though proportional to, mass
  3. Explore and describe the densities of various materials through measurement of their masses and volumes


  • Triple beam balances
  • Calculators
  • Different "fun sized" candy bars (Snickers, Milky Way, and 3 Musketeers recommended for their rectangular prism shape)
  • Copies of the Lab Sheet
  • Rulers
  • Hand lenses (optional)


mass, volume, density, weight, physical properties


Prepare enough materials on trays for student groups prior to the lab. Before beginning, the review procedure with student groups using provided lab sheet. This lab is self-paced. You may also want to review how to find the volume of a rectangular solid by demonstrating L x H x W. I always tell students that they are not to taste anything as it is a lab setting and the candy bars are going to be handled. I keep a stash of fresh candy bars for the conclusion of the lab!

Lesson Procedure:

  1. Take online POP Quiz on Measuring Matter with students to assess what they already know about the topic.
  2. View the Measuring Matter Movie on BrainPOP. Pause to discuss concept of density and its relation to mass and weight... Which are constant? (mass and density) Which depend on the pull of gravity? (weight). If a smaller piece/section of matter was removed from a solid object (i.e. a hunk of cheese), do both have the same mass? (no) Do they have the same density? (yes) Why?
  3. Grouping two pairs of students per lab table, provide each pair with one candy bar of each, a ruler, and calculator. Each group can share a balance. Examining the candy bars, students should hypothesize which one has the greater density and why. Record on lab sheet. Students should then document the materials and procedure of their experiment that they will follow.
  4. After discussing physical properties, students can use optional hand lenses to fill in table of differing characteristics of the candy bars. *Be prepared for creative ways to describe "brown" and the smell of chocolate!
  5. Students then calculate the volume of each candy bar to the nearest tenth of a centimeter (mm). Also record the mass of each to the nearest tenth of a gram.
  6. Using data, calculate the density of each candy bar using the units gram/cubic centimeter.
  7. Students may use workspace to show diagrams, calculations, etc. while also stating their conclusions based on their data. How did each hypothesis hold up?
  8. After the lab, student groups can evaluate their lab experience using the PLUS/DELTA section by listing events they were pleased with (cooperation, record keeping, descriptions, etc.) while also listing what could be improved on next time (accuracy, measuring, taking turns, etc.).
  9. Refer back to BrainPOP's other relevant movies and features to aid in clearing up any student misconceptions, or for review at the end of the lab or in the following days.
  10. At the end of the lab, have students retake the POP Quiz (either online as a class or printed) to check student understanding. Students can check their own answers or swap papers if using the printed version, or hand in for you to score.
  11. You may collect the lab sheets and POP Quiz sheets (if used) for scoring based on your evaluation of lab sheet sections. Total earned points in each section with a maximum of 20!

Extension Activity:

Using Tim's demonstration as an example, have students find the mass of irregular objects by water displacement in a graduated cylinder or beaker.
  • vasichek

    Is there a way to get a “printer friendly” version of the lab to avoid the headers, footers, and margins? Thanks!

    • agardnahh

      @vasichek, thanks for asking, this is not yet available, but is something that we’re working on. We appreciate that you took the time to make the suggestion.

  • strausj

    I was wondering if you have another suggestion of what I can use besides these candy bars. I love this experiment but have students with peanut allergies. Thanks for your help!

    • cemignano

      Hi strausj! You could try this experiment with cubes of cheese or different types of square cereal. Or, you could use other candy that is square or rectangular- Starbust, Now & Later, Laffy Taffy, etc.