• Assess comprehension of the steps and sequence of the scientific method through observation of group discussion and, a review of handouts, and individual student questions.

• Assess accurate measuring through observation.

• Collect worksheets for individual assessment.

Prior to this lesson, take three digital photos of an area of your school where shadows can be seen. Make sure that the photos are taken at three different times during the day and that shadows can be seen. Make sure the time stamp is covered when the photos are displayed to students. This will be removed at a later time. Display the photos without commenting. Allow students time to observe each photo. After allowing time for observing the photos, ask the following questions: “Do you have a question that could be asked about these photos? What do you observe about these pictures? We learned in the previous lesson how important it is to make good observations. Look at these pictures again and tell me if you observe anything else about this picture.” You want students to look at the pictures and begin to make comments about the shadows that are visible in the photo. Once students have made comments about the photos ask: “What are some questions you would ask about these photos?” Students may ask questions such as: Who took the photo? Who is in the photo? Where were the photos taken? When were the photos taken? Tell students these are all very good questions based on observations. Ask students, “Which one of these questions can we answer through an investigation?” Allow students time to think about this question. If they cannot answer this question, tell them they are going to find out when these photos were taken by conducting an investigation.

Show the PowerPoint Slides 1–8 as a review. Be sure to go over any vocabulary students may need at this time. Then show slides 9–12 to explain how the process of making observations helps a scientific experiment of investigation. Also, review how to set up graphs to display data. Finally, tell students that at the end of their investigation they should be able to answer the question based on data. They should be able to draw logical conclusions and may have new questions to ask.

Activity 1, Day 1: Following the Sun

In this activity students will observe and record the path the sun takes throughout the day (at least three times). Begin the activity:

1. Place a large white sheet of bulletin board paper on an easel. Tell students they are going to go outside and make an observation. They are to take their science journals with them to record their observations.

2. Take students outside and find a landmark that will be used for this activity. It can be a tree, flagpole, or playground equipment. Make sure that the area will allow enough space for students to observe and record their observations during these three times. The suggested times are 9 a.m., 11 a.m., 1 p.m.

3. Tell students they will be observing the object three times during the day. Go over safety rules such as allow space for each other, listen and follow directions, use low voices as to not to disturb other classes. Most important rule: Never look directly into the sun.

4. Have students sit so that they can observe the easel as you say: “Let’s look at this flagpole (used as an example). I am going to draw the flagpole and other things that I see.” Note: Do not include the shadow. “Is there anything else that I need to place in my picture?” Lead students to conclude the object’s shadow is missing.

5. Once students have established that the shadow is missing, draw the shadow in the picture. Tell students to stand in place and notice their shadow. Note: Do not tell students which way to face. Have them explore which way to stand so that they are able to see their shadow. If they have trouble you will want to make sure students are facing south. Tell students that you want to know where the sun is without looking. How can they tell you where the sun is in the sky without looking directly into the sun? Students may say to look at the shadow but does that really tell you where the sun is? You want students to tell you that the sun is on their left side as they face the flagpole.

6. Remind students not to look directly into the sun but ask, “Where is the sun in relation to the images in the picture?” Draw the sun into the picture.

7. Repeat this activity two more times during the day. Students are to make each observation on the same sheet of paper. Each time make sure students observe and record the position of the shadow and the position of the sun.

8. When three observations have been made, have students look at their drawings so that they now have a sequential view of the object and its shadows. Have students draw where they think the sun would be during the times they did not make the observations. Ask, “Do you notice anything about the movement of the sun? Can you predict the placement of the sun and shadow an hour from now? Two hours from now? How could you find out?” Students should see that a pattern is beginning and the sun is moving in an arc.

Discuss the variables present in the activity by asking students to name things that changed from the three different times they made observations.

“Did the sun change its position?”

“Did the shadow get bigger or smaller or did it move?”

“What caused these changes?”

Collect students’ responses and stress the importance of identifying which change caused the other to change. The changing position of the sun caused the shadow to change.

“Which change is the dependent variable?” length of the shadow

“Which change is the independent variable?” position of the sun

Show the pictures used at the beginning of the lesson. “Remember one of the questions we wanted to answer was, when were the photos taken? What did we learn that would help us answer this question?” Display the time stamp and show students the time the photos were taken and see if students were able to find out the time by relating their investigation to answer a question.

Give each student a copy of Tracing the Sun student sheet (S-4-6-2_Tracing the Sun.doc). Have students complete the paper and discuss their responses.

Activity 2, Day 2: Collecting Data on Shadows

In this activity students will track the sun by creating and using graphs to display the results. Prior to conducting the activity, select an area such as a parking lot or concrete area where the cans will not be disturbed and students can record their findings and measure their findings.

1. Place students in pairs. Give each pair a dowel, can, and a small amount of rocks or pebbles.

2. Instruct students how to set up the can by placing the dowel in the center of the can and place the rocks or pebbles around the dowel. Make sure the dowel is secure and can stand straight.

3. Students will take their container outside to the designated area. They are to mark the location of their cans so that the cans are placed in the exact same location when additional observations are made.

4. Students are to again place the can/dowel in the correct position so that a shadow is cast onto the pavement.

5. Tell students that they are to use their sundial to identify the sun’s path and tell time.

6. Tell students that one person will mark the top shadow of the dowel while the other partner measures the distance of the shadow from the can.

7. Students will repeat this measurement every hour and record the data.

8. When the last measurement is made have students create a graph to display their data.

Class Discussion

“Look at your graph. What do you notice about the graph? Do you see a pattern? What can you tell me about your first and your last measurement? Why do scientists rely on data to answer questions? Is it only important to make good observations? What else do scientists do while conducting investigations?”

Give each student a copy of Where Is the Shadow? sheet (S-4-6-2_Where Is the Shadow.doc). Have students complete the paper and discuss their responses. Make mention that the changing shadow is due to the movement of the Earth, not the sun.

Extension:

• Challenge students to locate an object at home and observe it in relation to the sun during the weekend. Does the sun’s path compare to the path observed at school?

• Have students cut out yellow circles to represent the sun and have students place the circles at marked spots indicating the location of the sun. Students will then trace the path of the sun.