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Lesson Plan #:AELP-INT001
Author: Leslie S. Gordon
Email: lgordon@northstar.k12.ak.us
School or Affiliation: University of Alaska, Fairbanks, AK
Endorsed by: Alaska Science Consortium and the Columbia Education Center Date: March 1, 2002

Grade Level(s): 2, 3, 4, 5, 6, 7, 8


  • Interdisciplinary
  • Science/Geology
  • Mathematics/Measurement
  • Language Arts/Literature/Children’s Literature

Duration: 5 class sessions

Description: This 5-day unit provides a variety of activities for students to observe, sort, and classify rocks. This unit can also be done with any type of object (seeds, leaves, tools, shells) that you have available to complement your curriculum.

Goals: Alaska State Content Standards :

  • Science Standard B1 – Use the processes of science; these processes include observing, classifying, measuring, interpreting data, inferring, communicating, controlling variables, developing models and theories, hypo-thesizing, predicting, and experimenting.
  • Science Standard A2 – Understand the physical, chemical, and nuclear changes and interactions that result in observable changes in the properties of matter (Changes and Interactions of Matter).
  • Math Standard A2 – Select and use appropriate systems, units, and tools of measurement, including estimation.
  • Math Standard B4 – Develop and apply strategies to solve a variety of problems.


  • Students will be able to make quantitative and qualitative observations of their rocks.
  • Students will be able to construct a Venn diagram or dichotomous key to classify their rocks.
  • Students will be able to estimate the mass of all the rocks in their group and rank them accordingly.
  • Students will be able to check the estimations of mass using a balance without gram masses.
  • Students will be able to use gram masses to determine the actual mass of their rocks.
  • Students will be able to find the volume of their rocks by using water displacement.
  • Materials:

    • Everybody Needs a Rock by Byrd Baylor
    • selection of rocks
    • blindfold for each child
    • balances
    • gram masses
    • rulers
    • centimeter grid paper
    • large graduated cylinders
    • water
    • buckets
    • large chart paper for dichotomous keys
    • masking tape
    • marking pens
    • Decision Matrix
    • Observation Log
      Handouts in .pdf format; requires free Adobe Acrobat Reader.

      Click the icon to obtain the free Reader.


    Day 1 :

    Gear Up (Introduction):
    Ask students what they know about rocks. List students’ comments on the board. Ask students to describe what they think are some important properties of rocks. Read Everybody Needs a Rock by Byrd Baylor.

    Explore 1:
    Begin the activity in one of three ways:

    • Have students go outside and collect three different rocks that they like. If they have studied the three types of rocks (sedimentary, igneous, metamorphic), then they should try to find one of each.
    • Have students bring in three rocks from home that they like.
    • Bring in rocks for students and have them select three rocks that they like. (This may be necessary in midwinter or where students do not have access to rocks)

    Pass out the Decision Matrix. Ask students to use the matrix worksheet to establish three criteria for selecting their own rock. Under the choices column, they should list their 3 rocks in such a way that they will remember which is which. Depending on the level of the class, you may want to generate a class list of criteria first (good color, good size, good shape, smoothness, etc). The rock with the most plusses is generally the best selection. If there are ties, have the children go back and double plus or minus any they feel especially strongly about.

    Have students share their selection criteria and the rock they selected. Ask them questions about how they decided on their criteria and how they decided how to break ties, etc. (Emphasize the reasoned decision making aspects here.)

    Explore 2:
    Next have everyone get into groups of four or five. Each person should observe his/her rock carefully and record observations on the Observation Log. These observations should be quantitative (involving measurements) as well as qualitative (five senses and descriptive words). If you want to do vocabulary development here, you can provide a thesaurus to help students come up with more adjectives.

    After they have done their observations, have students infer what forces or events might have caused their rock to be the way it is (size, shape, color, texture, gloss). Next have each member of the group put their rocks in the center of the table. Mix the rocks up. Ask the students to find his or her own rocks. After they can do that successfully, tell them they have three minutes to study their rocks again before they have to put on blindfolds and identify their rocks without looking (using two senses – touch, smell). When they can do that, put the rocks from the entire class together in a pile and let the students try to find their own.

    Ask students what strategies they used to help them find their rock when they could see. Ask them what strategies they used to help them find their rock when they could not see. How did they have to observe differently when they could not use their eyes? Discuss. Remind students that observation means using all five senses, or at least four. Ask students why they think their rocks are different. Why aren’t all rocks alike? Discuss the different things that effect the size, shape, color, mass, etc. of rocks. Introduce and/or integrate the vocabulary of igneous, metamorphic, and sedimentary here. Start a list of rock attributes (how rocks can vary) to help with classification.

    Day 2 :

    Have students combine all three of their rocks with the rocks of the rest of their group, then selecting 10 rocks to classify together. Next have students construct a Venn diagram (for primary students) or a dichotomous key (for older students) so that each of their rocks is keyed into a unique category.

    Have students share their classification systems with the class. Discuss. Add to the list of rock attributes if appropriate.

    Day 3 :

    Next have students work in their same small groups. Each student should put his or her favorite rock (one per person) in rank order with the rest of the rocks by estimating the mass (weight on earth) of each using feel only . After this is done, they can check their ranking using a balance, but no gram masses . Finally, have each group use masses to find the actual mass of their favorite rocks and make a graph of the results.

    Ask the students to share their problem solving strategies and their results. Ask what skills they think they need in order to make a good estimation. Ask if their predictions about mass of the rocks when they ranked them were correct.

    Day 4 :

    When students have found the mass of their favorite rocks, challenge them to come up with a way to find the volume. First have the children predict the cubic centimeters of their rock. (I usually provide centicubes for this.) Discuss the strategies they used. Then give them large graduated cylinders or other containers so they can find the volume by using water displacement (1 ml of water equals 1 cubic cm. of rock). If the cylinders are glass, be sure to put paper toweling in the bottom of the cylinder and tie a string on the rock to protect the glass from breaking .

    On Day 5 the following assessments can be used:

    Performance Task:
    Provide students with a variety of materials (clay, flour, gravel, sand, bones, etc.). Have students make a sedimentary, an igneous, and/or a metamorphic rock using the correct processes.

    Have students observe their three rocks quantitatively and qualitatively and infer how it might have gotten to have the properties that it has. (This could be done through a fiction story about the life of their rocks, a play, poem, song, etc., as long as it covers the criteria you establish).

    Teacher Checklist:
    Observe students during the entire unit and record their abilities to use key skills identified in the beginning of the unit. For example:

    • Observe qualitatively
    • Observe quantitatively
    • Predict
    • Infer
    • Classify using Venn diagrams and/or dichotomous keys
    • Measure
    • Work cooperatively to problem solve

    Useful Internet Resource:
    * Alaska Content Standards