Mini-Unit:
Rock On

Performance Standard B1, Level 1

Students observe and describe their world.

Key Concepts and Skills

• There are similarities and differences in nature.
• Measurement can be done in a variety of ways.
• Students can use the processes of science including observation, classification, measurement, and prediction.
• Rocks come in many sizes and shapes.

Timeline

This can take place over two or three weeks.

Abstract

Students observe and measure rocks in order to classify and infer usage from their characteristics.

Materials

• Collection of rocks (local, purchased, or AMEREF Minerals Kit )
• Assorted materials to use when designing tools
• Equal-arm balances
• Chart paper
• Markers
• Graph paper (1" squares)
• Yarn or hoops
• Small plastic bears, unifix or wooden cubes, tiles, etc.
• White paper
• Hand lens or magnifiers

Activities

1

Teacher brings in a box of assorted rocks. Students play “20 Questions” about the contents of the box. After contents are guessed, the rocks are distributed among students and they observe the rocks using their eyes, hands, lenses or magnifiers. Ask students such things as how are they alike, how are they different, what words would you use to describe the rocks? Record responses on chart paper for class to see. Place rocks in a science center in the classroom.

2

Teacher has whole class gather around and places 16–20 assorted rocks in a pile on a piece of paper. Have a student choose an attribute such as small. Move all the small rocks into a pile, label it small, and draw a circle around it. Place the other rocks in a pile, draw a circle around it and label it not small. Keep dividing the piles using properties (shiny, not shiny; rough, not rough; heavy, not heavy) until you have used all the rocks you started with. Give each student group (three to four students) 16–20 rocks. Ask them to create their own classification system. *This is an example of binary classification. (*As students are grouping their rocks, the teacher walks around with a checklist to assess how students are doing with their classifying skills. Any type of classification should be accepted as long as the student can justify it.)

3

Ask a student to choose 10 rocks that have several attributes and bring them from the science center to a place that has a Venn diagram set up (a Venn diagram can be created by using yarn or plastic hoops). Students gather around and together they will choose two rules to sort the rocks (like big and jagged). Write the rules on a folded piece of paper that can be placed in the circles. Students decide where to place the 10 rocks according to the rules. Ask students what they notice about the rocks in each circle. Guide them if necessary to the conclusion that some rocks fit both of the rules and should be placed in both circles. Ask how a rock could be in both circles at the same time. If students do not come up with moving the circles, begin to overlap them. Spend some time asking questions that lead to student understanding of the “intersection” of both circles. When students have an understanding, ask them to place the rocks according to the chosen rules. Repeat this again and again choosing different attributes to use in sorting. (This is another opportunity for teachers to do a short check to find out at what level students can use a Venn diagram.)

4

Students will look at specific attributes of rocks and use them to sequence the rocks (e.g., lightest to darkest; smallest to largest). Students begin with three rocks and then work up to using five rocks. Students use a gold dredge worksheet like the one below to draw their rock sequence.

5

Give students graph paper with at least one-inch squares. Tell them to choose a rock and place it on the paper. Ask students how many squares big their rock is. Students choose three more rocks to repeat the procedure.

6

Choose two or three students to come up in front of the class and hold two different size rocks. Ask which rock is heavier? How they can tell? Ask the students if they know of other ways to measure how much things weigh. (Hopefully they will come up with using balances). Provide students with an equal-arm balance and cubes, bears, tiles, etc., that they can measure. Students will weigh three to five different items and record their findings.

7

Brainstorm ways that rocks could be used by people and animals. Chart the ideas given by the students. Invite community people to come into the classroom to discuss traditional uses of rocks (e.g., communication, tools, fishing, hunting, etc.). Using their knowledge of rock characteristics, students investigate and design a tool using a rock. Display student work.

 

Expanded Sample Assessment Idea

Procedure

Students will:

1. Collect rocks at home and school.
2. Divide into groups of two to three; take a group of 8–12 rocks and classify them by criteria of their group’s choosing. This could include color, size, shape, texture, use, and so on. Groups will share with each other the ways they classified the rocks. Each group will then go back and create a different way to classify their rocks. Each group should guess the other group’s new classification.
3. Draw how their group classified a rock of their choice and include details like color, shape, and size.
4. Discuss volunteers’ pictures in circle group.

Reflection and Revision

Use comments about pictures and redraw their rock classification.

Level of Performance

Student did not complete classifications and could not tell why. No drawings completed. There is no evidence of elaboration or extensions. There is evidence of misconceptions.

Standards Cross-Reference
(Alaska Department of Education & Early Development Standards)

National Science Education Standards

Employ simple equipment and tools to gather data and extend the senses. In early years, students develop simple skills, such as how to observe, measure, cut, connect, switch, turn on and off, pour, hold, tie, and hook. Beginning with simple instruments, students can use rulers to measure the length, height, and depth of objects and materials; thermometers to measure temperature; watches to measure time; beam balances and spring scales to measure weight and force; magnifiers to observe objects and organisms; and microscopes to observe the finer details of plants, animals, rocks, and other materials. Children also develop skills in the use of computers and calculators for conducting investigations. (Page 122)

Use data to construct a reasonable explanation. This aspect of the standard emphasizes the students’ thinking as they use data to formulate explanations. Even at the earliest grade levels, students should learn what constitutes evidence and judge the merits or strength of the data and information that will be used to make explanations. After students propose an explanation, they will appeal to the knowledge and evidence they obtained to support their explanations. Students should check their explanations against scientific knowledge, experiences, and observations of others. (Page 122)

Communicate investigations and explanations. Students should begin developing the abilities to communicate, critique, and analyze their work and the work of other students. This communication might be spoken or drawn as well as written. (Page 122)

Simple instruments such as magnifiers, thermometers, and rulers provide more information than scientists obtain using only their senses. (Page 123)

Scientists develop explanations using observations (evidence) and what they already know about the world (scientific knowledge). Good explanations are based on evidence from investigations. (Page 123)

Benchmarks

People can often learn about things around them by just observing those things carefully, but sometimes they can learn more by doing something to the things and noting what happens. (Page 10)

Tools such as thermometers, magnifiers, rulers, or balances often give more information about things than can be obtained just by observing things without their help. (Page 10)

Describing things as accurately as possible is important in science because it enables people to compare their observations with those of others. (Page 10)

Ask “How do you know?” in appropriate situations and attempt reasonable answers when others ask them the same question. (Page 298)