Chocolate Bars of Density

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Lab Sheet One
Lab Sheet Two
Lesson Rubric
Student Sample One
Student Sample Two
Student Sample Three

Name: Darlene Bissonette
Grade: 9th
Subject: Earth Science
School: Brasher Falls Central High

  1. Title/Context Of Learning Experience
    Students will examine and determine the density of solids. When working with the density of solids the students will complete all the steps to find the density of different size pieces of a chocolate bar concluding with the realization that density of a substance remains the same even when size of the substance changes

    Standard MST1: Analysis, Inquiry, and Design
    Students will use mathematical analysis, scientific inquiry, and engineering design, as appropriate, to pose questions, seek answers, and develop solutions.

    Mathematical Analysis

    Key Idea MST1.MA1:
    Mathematical Analysis: Abstraction and symbolic representation are used to communicate mathematically.

    Commencement

    Performance Indicator MST1.C.MA1A:
    Students use algebraic and geometric representations to describe and compare data.

    Major Understandings 1.1a
    Use eccentricity, rate, gradient, standard error of measurement, and density in context.

    In class an introduction to the scientific method and density will take place in chapter one of the textbook. The students will also use their reference tables to look up the formula for density. Students should know how to divide, and what the terms horizontal and vertical mean.

  2. Essential Question
    When you break your candy bar into pieces to share with your friends does the density change?
  3. Procedure
    Students will be given the Chocolate Bars of Density lab to read before they come to lab.

    Day 1
    For safety reasons the candy bars that the students’ use in lab will be placed on clean pieces of paper towel.

    Students will complete the lab work individually, however, for introduction to some topics think pairs may be used. Students will come up with a hypothesis and review how to find volume of a rectangle in think pairs. Two pairs will come together and share their thoughts with each other, one person will report to the class. An overview of how to use the electronic balance will be given by the teacher. The students will write down the procedure they are going to use for this investigation or write it down as they go along. The students will then carry out their procedure and record needed data for the data table. Before any student can eat their candy bar they must have their data approved by the teacher.

    Day 2
    The teacher will lead a discussion of the density formula by modeling it for the class. Using the SMARTboard all groups will post their data at the front of the room so as to compare results. A student will take the lead and demonstrate on the smart board how to solve for volume with the data collected.

    Day 3
    With student and teacher input, a student will model how to set up their graph using the SMARTboard. After the graph is made students will discuss in pairs and then in groups the relationship they found and relate the relationships back to their hypothesis. Each group will share their results with the class and students will have time to write down and if need be adjust their conclusion. Students will then independently work on the three analysis questions and when finished turn them in to their lab folders.

  4. Resources
    Earth Science Geology, the Environment, and the Universe New York Edition Textbook - Glencoe 2005 0-007-868352-1New York State Reference Tables for Physical Setting/Earth Science

    All material lists are found on the lab pages.

    Written by:
    Mr. David Robison
    email: drobison@wilson.wnyric.org
    Regents Earth Science Teacher
    Wilson High School
    Wilson, New York 14172
    School: (716) 751-9341

    STANYS SAR
    Northwest Section
    DLESE Ambassador
    BAP Point of Contact

  5. Instructional/Environmental Modifications
    • Extra time available from 2:30 pm –3:25 pm most school days
    • A teacher’s aid is available for two out of the six days first period of the day.
    • If you have student(s) who are allergic to chocolate bars graham crackers would make a good substitution.
  6. Time Required
    Students meet for lab every two out of six days, and periods are 41 minutes long. This lab took three full lab periods.
  7. Reflection
    I used this lesson to help students better understand the density of solids. I was pleased that a month and a half later as a result of this lesson the students understood the basic principle of density; that changing the size of the object does not change the density. I learned that the students I have in lab need more work on graphing, including but not limited to: setting up the axis, labeling the axis, and plotting points. I also learned that when I ask the students “Are your values for density the same or different?” They answered different at first. Their values for density might have been something like 1.0 g/cm3, 0.9 g/cm3, 1.1 g/cm3, 1.2 g/cm3, 1.1 g/cm3. The students saw these values as different, while I determined those values to be insignificantly different or approximately the same.
    Unfortunately the SMARTBoard was not installed at the time this lesson was taught. Instead I used a projector that could be seen on an overhead screen. On the screen I taped large white paper to write on. The students wrote their data on the blackboard. Due to lack of time the students were not required to type the lab report up.