Making Conclusions

Grade Levels

4th Grade
Related Academic Standards

Academic standards haven't been assigned to the lesson plan.
Assessment Anchors

Assessment anchors haven't been assigned to the lesson plan.
Eligible Content

Assessment anchors haven't been assigned to the lesson plan.
Big Ideas
Concepts
Competencies

Objectives

In this lesson, students demonstrate how the sun’s path can be used to tell time. Students will construct a personal sundial to collect data. Students will:

construct an instrument to trace the sun’s path.
observe the path of the sun.
draw logical conclusions based on data.
make inferences based on repeating investigations.

Essential Questions

Vocabulary

Horizon: The line where the earth and sky seem to meet.
Shadow: The dark area that is made when rays of light are blocked by person or thing.
Sundial: An instrument that consists of a plate with numbers and a point that casts a shadow. It shows the time of day by the movement of the shadow.
Gnomon: The pointer or stick on a sundial. Its shadow is used to tell time.

Duration

30–45 minutes/2 class period (plus two observation times done during the day)

Prerequisite Skills

Prerequisite Skills haven't been entered into the lesson plan.

Materials

Sundial Example (S-4-6-3_Sundial Example.doc)
large Styrofoam or drinking cup with a plastic lid, one per student
drinking straw, one per student
watch, one per group
permanent marker, one per student
pencil, one per student
tape, one roll per class
student journal, one per student
small pebble or rock, one per student
compass, one per class

Telling Time by the Sun (S-4-6-3_Telling Time by the Sun.doc)

Related Unit and Lesson Plans

Related Materials & Resources

The possible inclusion of commercial websites below is not an implied endorsement of their products, which are not free, and are not required for this lesson plan.

Various sundials found in Pennsylvania:
http://www.waymarking.com/waymarks/WM8VY3_Sundial_George_School_Newtown_PA

http://www.waymarking.com/waymarks/WMV3A_Old_Main_on_Penn_State_Campus

http://www.waymarking.com/waymarks/WM1XC1

Formative Assessment

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- During the shadow investigation observe how students set up the investigation.
- Monitor their placement of the cups and the collection of data.
- Listen for understanding as students’ observations can lead to questions that may or may not be answered through investigations.

Suggested Instructional Supports

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Scaffolding, Active Engagement, Modeling, Explicit Instruction

W:	The main focus of this lesson is making observations to answer questions about a natural phenomenon such as the sun rising and setting in the sky. Students learn that this interest in knowing about the sun’s path across the sky began many, many years ago.
H:	The lesson begins with reading about how people in ancient times used various ways to tell time. They are introduced to a device used to tell time, a sundial.
E:	Students will use everyday material to create a sundial. They will use the constructed clock to try to tell time. They will make the connection between telling time and the path of the sun.
R:	Students will apply their understanding of how the sun travels through the sky to answer the questions about the relationship between the sun and time. Students will revisit questions posed at the beginning of the lesson: How does a shadow tell time?
E:	Students’ sheets at the end of the lesson provide students the opportunity to show what they have learned.
T:	At the beginning of the lesson students were shown how ancient people tried to answer the question “How does a shadow tell time?” Students also try to answer the same question by conducting a scientific investigation.
O:	This lesson is organized so that in the beginning students see the history of telling time using a sundial. Students are asked to perform a task using their prior knowledge. The lesson moves to teacher-guided instruction, with the construction of a sundial and finally students testing their sundial as an instrument to tell time. Finally, students complete a summary worksheet.

Instructional Procedures

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Activity 1, Day 1

This lesson will focus on the use of sun as a device for telling time. Begin the lesson by reading about how people in early times used various ways to tell time. “As early as 800 B.C. Egyptians were building devices to mark time. It was the Greeks who developed and constructed complex sundials using geometry. Today sundials are used mostly for decoration and placed in gardens. We are going to construct a sundial to answer questions and collect data. A question we want to know is: How does a shadow tell time?”

“In our previous lesson we learned that the sun travels in a path across the sky. Now we want to find out if we can accurately record time on a device.” Guide students as they construct a sundial. Note: A compass is needed in this investigation and you may find magnetic north for students and indicate N so that students have a starting point to place their cups. However, the time will not be accurate due to the fact that there is a difference between magnetic north (the magnetic field of the earth) and geographic north (the direction of the earth’s North Pole). If you choose to use geographic North, you must locate the North Star at night and mark an arrow on the ground that points toward the North Star.

Construct a Personal Sundial

Review the illustration of a student-made sundial (S-4-6-3_Sundial Example.doc).
1. Give each student a cup with a lid, a straw, marker, and a small rock or pebbles.
2. Have students measure two inches from the top of the cup and make a mark using a permanent marker.
3. Using a pencil, have students gently poke a hole in the side of the cup.
4. Place the rock or pebbles in the cup. This will keep the cup secure and keep it from blowing away.
5. Place the lid on the cup.
6. Place the straw through the hole in the lid then through the hole at the side of the cup.
7. Secure the straw with tape.
Discuss with students what they learned in the previous lesson about the sun’s path. Students should be able to say that the sun travels in an arc. They may also say that this is a pattern that is repeated every day.
1. Tell students they will take their individual sundials and place them in a sunny area. They will go to their individual sundial and find the shadow of the straw on the lid. Then they are to make a mark (a dot) with a permanent marker to indicate a point on the cup where the shadow is. Remind students that they will want to create an arc with their dots.
2. Have students record dots on the lid each time they make an observation.
Activity 2, Day 2

Have students look at their personal sundials they created previously. Ask students if there is a comparison to the marks on their lid and the sun’s path they saw in previous lessons.
1. Tell students that they will once again place their cups outside in the same spot they had the day before.
2. They will go outside at the same time they went out previously.
3. Mark the shadow again with a different color marker.
4. They are to observe the mark on the lid and compare the mark with the exact time. Are the marks the same?
Class Discussion

“When a scientist conducts investigations what should s/he do? Why is it important to collect exact data? Why is it important to revisit an investigation? What does the data tell you when you get different results? In these lessons we looked at different investigations, who remembers what we were doing in these investigations? What should your investigation do?”

Give each student a copy of Telling Time by the Sun (S-4-6-3_Telling Time by the Sun.doc). Have students complete the paper and discuss their responses.

Extension:
- Challenge students by having them record the shadow of a landmark in the schoolyard such as a tree or flagpole. Students will observe if the shadow cast by the landmark is always at the same location at the same time during the year.
- Work with students inside the classroom using a flashlight and have students create shadow puppets. By changing the position of the flashlight, students will observe the shadows and record changes by tracing the shadows on white paper.
- For students performing above and beyond the standards, have them create a graph representing the time of day with the length of the shadow created from the sun. Students may need assistance in setting up the graph so assist them in creating the graph structure and guide them through the process. When completed, discuss the role of each variable and examine which variable affects the other. Also, discuss what improvements could be made to make this experiment more valid.

Making Conclusions