Dial up the Sun! Patterns on Earth and in Space

Time Required: One 45 minute session, which must be followed up over 6 consecutive hours. *Conduct this activity on a sunny day!
Skill Level: Beginner
Recommended Grades: 3rd to 5th

In this activity, students will work in pairs to design an innovative gnomon for a functional sundial. Students will record data regarding their observations about the length and position of shadows cast by the sun over a series of 4 hours. Based on this data, students will make inferences regarding patterns to predict the length of the shadow and its position over the next 2 hours.

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Lesson Plan


Step 1

Ask: Can you create an accurate sundial to tell time by the hour?

Step 2

Project your computer or tablet screen to display images of traditional sundials from a safe Google search.

Step 3

Ask students to share all they know about sundials. Record their responses.

Step 4

Define the term "gnomon" as the projecting piece on a sundial that display the time by the position of its shadow. Share what attributes the gnomons in the images have in common. (Possible responses: They are triangular blades or sticks.)

Step 5

Share the goal: Students will work in pairs to design an innovative gnomon for a sundial they will use to track the time over the next 4 hours. Their sundial will display the time based on the position of shadows cast by the sun.

Step 6

Share materials: paper plate, paper, pencil and 3Doodler.

Step 7

Ask students to predict if a different shape would work just as well or better as a gnomon.

Step 8

Set base criteria for gnomon: The length of the gnomon should be equal to the radius of the paper plate. Explain that this is the distance from the center of the plate to its edge.

Step 9

Model how to create a stencil / template for an innovative gnomon. Vary its shape.

Step 10

Use the 3Doodler to trace and fill in your gnomon.

Step 11

Use the 3Doodler to weld your gnomon down to the center of the paper plate.

Step 12

Tape the sundial down in front of a windowsill where it will receive plenty of sunlight.

Step 13

Trace the shadow of your gnomon using a ruler to draw a straight line from the gnomon to the edge of the plate. Record the time.

Step 14

For the next 4 hours, have students record the time in the same way. As students work, circle to assist and assess.

Wrap Up

Have students mark the plate to predict where and how long the shadow will be twice over the next two hours. Check over the next 2 hours to see if their predictions were correct. Discuss how they made their predictions. What patterns did they observe? Share on Twitter #3DoodlerEDU


Review student’s sundials and recorded observations to determine their level of understanding.

Possible Extensions

Students will create a simulation of the earth's rotation around the sun using a lamp and taking digital images to animate as a stop-motion video. Discuss differences in the sun for different seasons and the corresponding effect on the sundial.


Possible Discussion Questions:
How does the sundial use Earth's movements to tell time?
How does the angle of the light change the direction of the shadow?
How did the shape of your gnomon affect the size or length the shadow cast?
Is there anything you could do to improve your gnomon?
What is the path of the sun as it moves across the sky?
Do you think that the path of the sun changes throughout the year? Explain.


  • gnomon - the projecting piece on a sundial that display the time by the position of its shadow.

Educational Standards

Common Core

Engage effectively in a range of collaborative discussions (one-on-one, in groups, and teacher-led) with diverse partners on grade 4 topics and texts, building on others' ideas and expressing their own clearly.

In This Lesson

Students will share predictions and ideas based on their observations throughout this activity.

Common Core

Pose and respond to specific questions to clarify or follow up on information, and make comments that contribute to the discussion and link to the remarks of others.

In This Lesson

Students will participate in discussions with their partner during this investigation, as well as with the whole group.

Next Gen Science

Earth's Place in the Universe: Represent data in graphical displays to reveal patterns of daily changes in length and direction of shadows, day and night.

In This Lesson

Students will record their observations based on the length and position of the shadow cast by the gnomon over the course of 6 hours.

CS Teachers

Plan and create a design document to illustrate thoughts, ideas, and stories in a sequential (step-by-step) manner (e.g., story map, storyboard, sequential graphic organizer).

In This Lesson

Students will create sketches and stencils while planning the 3Doodler design of their gnomon.

CS Teachers

Decompose (break down) a larger problem into smaller sub-problems with teacher guidance or independently.

In This Lesson

Students will break down the process of understanding the purpose of the sundial and the pattern of shadows cast by the sun by the earth's rotation.


Use technology to seek feedback that informs and improves their practice and to demonstrate their learning in a variety of ways.

In This Lesson

Students will use the 3Doodler to visually demonstrate how shadows cast by the sun can be used to tell time.


Exhibit a tolerance for ambiguity, perseverance and the capacity to work with open-ended problems.

In This Lesson

Students will demonstrate willingness and competency within an open-ended task with more than one possible outcome.


Create original works or responsibly repurpose or remix digital resources into new creations.

In This Lesson

Students will use a 3Doodler to innovate a new type of gnomon.


Use collaborative technologies to work with others, including peers, experts or community members, to examine issues and problems from multiple viewpoint

In This Lesson

Students will seek feedback from peers before creating a new species of reptile with a 3Doodler.

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