Title: Rocks and Their Properties: Day 1
Author: CAST
Subject: Science
Grade Level(s): 3–5
Unit Description
In this unit, entitled Rocks and Their Properties, students will engage in cooperative research projects in order
to learn about the properties of the three basic rock types and the processes that form them. In order to ensure
that students can express what they learned as accurately as possible, a variety of options will be available for
communicating their new knowledge.
This investigation of the properties of rocks should take 6–7 class periods. The UDL approach used in this unit
provides the following:
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presentational options to make information accessible to all students
varied strategies and techniques to reach all students
motivational options to ensure that all students can be engaged
flexible classroom management techniques that increase opportunities for all students
Lesson Description for Day
Today, students will explore the word morphologies of the three basic types of rocks, igneous, sedimentary, and
metamorphic, in order to have a mnemonic device for remembering the processes that form them. They will
then explore samples of the three rock types, share their findings, and determine what other types of information
they will need as they further their study of rocks.
State Standards
Massachusetts State Standards for Science and Technology/Engineering, Strand 1: Earth and Space Science
1. Massachusetts Science Standard 1.3: (Rocks and Their Properties) Identify three categories of rocks
(metamorphic, igneous, and sedimentary) based on how they are formed, and explain the natural and
physical processes that create these rocks.
2. Massachusetts Science 1.6: (Earth's History) Describe and give examples of ways in which the Earth's
surface is built up and torn down by natural processes, including deposition of sediments, rock
formation, erosion, and weathering.
Goals
Unit Goals:
1. Students will describe the natural and physical processes that create metamorphic, igneous, and
sedimentary rocks.
2. Students will successfully complete a cooperative research project that refines their basic understanding
of rock formation processes.
3. Students will apply their understanding of the processes that create sedimentary, igneous, and
metamorphic rocks to making predictions about how the rock cycle could be impacted by changes in the
forces that contribute to rock formation.
Lesson Goals:
1. Students will gain a basic understanding of the three rock formation processes.
2. Students will effectively communicate results of their explorations of rock samples with others.
3. Students will develop a basic understanding of how the relative hardness of rocks can be tested using
simple tools, and that hardness is one characteristic applied to categorizing rocks.
Methods
Anticipatory Set:
In order to engage students' curiosity and expectations about rocks, invite the class to participate in the
following 'thumb's up–thumb's down' activity. Explain that you're going to make a statement about rocks and
that students should give a 'thumb's up' if the statement seems true and a 'thumb's down' if it doesn't. Remind
students that this isn't a quiz; it is just an informal way to begin a discussion of rocks. After each statement,
invite students to turn to their neighbor and briefly discuss why they responded the way they did. You may also
want to invite a volunteer to tally how many 'thumb's up–thumb's down'; responses were given for each
statement.
1. A rock you pick up off the ground is probably older than dinosaurs. [true]
2. Some rocks are formed deep in the heart of volcanoes. [true]
3. If you pick up a rock off the ground, you can tell if it came from your town or city by looking at the
layers of color in it. [false]
4. Sometimes rocks were made into tools by Native Americans and early settlers. [true]
5. Some rocks are formed when cast-off seashells fall to the bottom of a sea, and, over a long period of
time, pack together to form a rock called limestone. [true]
Introduce and Model New Knowledge:
Explain to the class that they will be working in small groups to conduct investigations into three basic groups
of rocks, and before investigations begin, you have some background information to help them get started.
Key Vocabulary:
Explain to students that they will be learning about three basic types of rocks: igneous, sedimentary, and
metamorphic. Discuss the three rock types by highlighting critical features of their word morphologies.
Knowing the origins of the words themselves will serve as a mnemonic device for students to remember the
processes that formed the rocks.
Use the blackboard, overhead projector, or Power Point slides in order to highlight the following information:
Igneous—this word comes from the Latin root ignis, which means fire. Link ignis to the more familiar word
ignite. Ask the class if this gives them a clue as to how igneous rocks are formed. Confirm that igneous rocks
are formed in the intense heat of the earth.
Sedimentary—Write sedimentary on the class blackboard. Ask the class if they can find a shorter word in this
long word [sediment]. Define sediment. Ask the class to turn to a neighbor and describe how they think
sedimentary rocks are formed. Confirm that sediment is gradually deposited in water, packed down over many
years, and becomes rock.
Metamorphic—this word has Greek origins. Meta means change, and morphic means structure. Ask students to
discuss with a neighbor how they think metamorphic rocks are formed. Confirm that metamorphic rocks start
out as one type of rock and that the intense heat and pressure of the Earth changes them into a different type of
rock.
Provide Guided Practice:
Pass around examples of all three rock types that you have collected for this lesson. Model how students, who
will work in small groups, can compare and contrast them in one of the following ways:
1. Use a hand lens to observe them closely, then sketch and write descriptions of what you see.
2. Try scratching them with a fingernail. Which rocks can be scratched? What does this say about their
hardness? Now, try scratching them with a penny. Which rocks can be scratched now? Since a penny is stronger
than a fingernail, what does that say about the rocks' hardness? What can you conclude about the relative
hardness of the rocks? [If they can be scratched with a fingernail, then they're softer than those that can only be
scratched with a penny. If a penny can't scratch them, then they're harder yet.]
3. Weigh the rocks, and use a tape measure to measure their diameter. What is the relationship between their
sizes and weights? Are some very small rocks also very heavy; are others very light? Keep track of each type of
rock, its weight, and diameter, so you can compare them.
Ask students if there are other characteristics they should think about when examining the rocks (i.e., how shiny
they are compared to each other, how angular, or possibly their degree of hardness).
Provide Independent Practice:
There is no Independent Practice in this lesson.
Wrap-Up
Pull the whole class back together, and discuss significant learnings from today's activities. Using a 'Think, Pair,
and Share' format (pose a question, have partners discuss, then invite volunteers to share with the whole class),
have students respond to these questions:
Assessment
Formative/Ongoing Assessment:
As students explore the rock samples, be available to clear up any confusion that they may have when
examining them. Help clarify the question about using a fingernail and a penny to evaluate the rocks' relative
hardness for any students who may be confused. During the lesson wrap-up, make a note of which students
seem confused and may need more guidance over the next few days.
Summative/End Of Lesson Assessment:
There is no summative assessment at this early point in the unit, just formative assessment.