Build a Sundial





Name of Activity Build a Sundial
Author STOMP
Keywords sundial, observations, revolution, earth, sun, rotation, axis, gnomon, solstice, equinox
Subject Non-LEGO
Grade Level 4, 5, 6
Time 1 Hour Total
Brief Description Students will build a sundial and record observations from it.
Lesson Objectives: This activity introduces students to various topics associated with the revolution of the earth around the sun and the earth’s rotation on its axis with respect to the sun.
Materials Needed: Paper plate
Popsicle stick
Preparation and Set Up: Gather the necessary materials.
Arrange students in pairs.
Distribute necessary materials.
Necessary Background A sundial can record one of two things. Either the sun’s position in the sky can be recorded at various stages throughout the day or the length of the shadow cast can be monitored at the same time everyday for a period of weeks or months. The lesson can be used to target either of these principles.

Gnomon – The object which casts the shadow.
Solstice – The day of the year that is has either the longest or shortest amount of daylight depending on the sun’s position in the sky (in the northern hemisphere the winter solstice is the shortest day and the summer solstice is the longest day).
Equinox – The two days of the year that fall midway between the Summer and Winter solstices. Day and night are almost equal.

  1. Start with an introductory discussion about seasons as determined by the sun. The summer and winter solstices, and the fall and spring equinoxes.
    1. Sundials support this theory by demonstrating that the sun’s rays are most indirect in the winter, when the sun is lowest in the sky and the day is the shortest. The shadow cast the the gnomon is the longest.
    2. The summer is the opposite. The shadow cast is the shortest.
  2. Introduce the idea of the Earth’s rotation.
    1. To us, it appears that the sun moves across the sky, but it is actually the revolution of the Earth on its axis.
  3. When the sun rises in the East it cast a shadow that can be tracked all day long as the sun moves from East to West.
  4. To make a sundial:
    1. Draw two perpendicular lines on the back of a paper plate that cross at the center.
    2. Designate one line to be north.
    3. Draw in a compass rose to label all the directions.
    4. Place a popsicle stick in the center and secure it with tape on the underside of the plate.
    5. You can either demonstrate with a flashlight how the sundial works or bring them outside.
      1. Have students mark where the dial is at a particular time of day (use a compass to orient the sundial).
      2. Let students go outside at different times of the day to test their sundial (be sure to always use a compass to orient the sundial).
      3. Do this activity over a month/year to see how the length of the shadow changes with the seasons.
Reference 1

Orbits of the Earth, Moon, and Sun





Name of Activity Orbits of the Earth, Moon, and Sun
Author Michael Hart, Usula Deelstra
Keywords earth, moon, sun, models, rotation, tilt, relative size, seasons, stars, size, motion
Subject Non-LEGO
Grade Level K, 1, 2, 3, 4, 5, 6
Time 1 Hour Total
Brief Description The class will explore the relation between the Earth, moon, and sun using classroom models.
Lesson Objectives: The Purpose of this activity is to discuss how the Earth, moon, and sun move relative to each other. And to discuss rotation, tilt, and relative size. In regards to relative size, a physical activity is introduced to help enhance the concept of the relation of the Earth, moon, and sun to each other.
Materials Needed: - Balloons.
- Tape Measure.
- Globe.
- Flashlight.
Necessary Background This activity deals with the orbit of the earth around the sun and the orbit of the moon around the earth. It takes the earth one year (365 days) to orbit the sun. At the same time, the earth is rotating about its own axis. The earth makes one complete rotation once a day. The combination of the rotation of the earth, its orbit about the sun, and the earth’s natural tilt cause seasons on the earth. For a more detailed description see This website contains information about the earth’s orbit, its rotation, and the seasons. Similar to the earth, the moon has an orbit and rotation also. A description of the moon can be found at


  1. Begin the activity by discussing facts relating to the Earth, moon and sun.
  2. Talk about how the three move relative to each other.
  3. Select three students to imitate the motion of the sun, Earth, and moon.
    1. Have the Earth stand in place and turn around, talk about how one turn is one day.
    2. Have the Earth walk one lap around the sun, imitating the passing of one year on Earth.
    3. Have the student carefully do both movements together.
    4. Next add the moon. Have the moon orbit the Earth, it takes 28 days for the moon to orbit the Earth. During this time we see all the stages of the moon.
    5. Finally, put all the movements together.
  4. Discus the tilt of the Earth, and how it produces seasons.
    1. Turn out the lights. Using the globe and flashlight have one student hold the flashlight representing the sun.
    2. Have a second student walk around the flashlight with the globe.
    3. Show students that as the globe moves around the sun, the northern or southern hemispheres will be tilted towards the sun, these are the different seasons.
  5. Discuss the relative sizes of the sun, moon, and Earth.
    1. The sun is the largest, but to us it appears about the same size as the moon because it is so much farther away.
    2. Have students break into groups of two.
    3. One student will get a small balloon and the other a larger balloon.
    4. The student with the small balloon will tell the student with the large balloon to walk backwards until the balloons appear to be the same size
    5. Finally, ask students to discuss the relationship between the size that an object appears and the distance from you that it is. Finally, explain that we “built” our own models today to explore the motion of the planets, engineers use models to understand systems like the solar system that are too big to make life-sized models to study.
Reference 1

Digital Measuring Wheel





Name of Activity Digital Measuring Wheel
Author STOMP
Keywords NXT, rotation, sensor, measurement, accuracy, diameter, circumference, pi, distance, conversion
Subject NXTs
Grade Level 4, 5, 6, 7, 8, 9+
Time 1 Hour Total
Brief Description Use an NXT and a rotation sensor to buld a digital measuring wheel. The device can be
pushed by hand on the ground or at a distance using a handle. Check the device’s
accuracy with a measuring tape.
Lesson Objectives: - To learn about programming in NXT MINDSTORMS.
- To use measurements and math in programming to collect data.
Materials Needed: NXT brick
NXT motor w/built in rotation sensor
LEGO wheel and axle
Computers running NXT-G MINSTORMS software.
USB cords to connect NXT bricks to computers
Data collection sheet
Preparation and Set Up:
- Arrange students in groups of two.

- Distribute necessary materials.
- Distribute a data collection sheet.

Necessary Background Measuring wheels are used in many places to find the distance of a line. The number of
rotations can be translated to distance if the circumference of the wheel is known.
The circumference can be found by measuring around a wheel or by multiplying the
diameter by pi.


  1. Have students build a measuring wheel device. Attach a wheel with an axle to a motor. Wire the motor to the NXT brick, but do not attach the motor to the NXT brick.
  2. Have students measure the wheel’s circumference to use when calculating distance.
    1. Option: You may also have the students find the circumference by measuring the diameter and multiplying the diameter by pi.
    2. Option: You may also discuss radius by having students multiply the radius by 2 x pi to get teh circumference
    3. Option: Have students find the circumference all three ways and compare answers.
  3. Have students program the NXT brick to display the distance traveled by doing the following:
    1. Divide the rotation degrees value by 360 to get the number of rotations traveled (or have the rotation sensor count in rotations) using the “Math” Block.
    2. Multiply that value by the circumference to get a distance value by using the “Math” block.
    3. Convert this distance value to a text value using a “Number to Text” block.
    4. Display the text value on the NXT screen using a “Display” block.
    5. You will need to enclose the program in a loop so that it is continuously displaying measurement data
  4. Check the accuracy of the device with a tape measure by having students measure the length of different lines.
  5. Discuss, as a class, reasons that the measurement may not be accurate. Does this always matter? How could you make the measurement more accurate?
  6. Discuss the different variables in this experiment.
    1. The independent variable is the number of rotations.
    2. The dependent variable is the measurement shown on the screen.
    3. Discuss as a class the relationship between these two variables.
    4. Option: draw a line graph of rotations v. acutal measurement (inches, cm, meters, etc.) that the NXT brick displays.
  7. Discuss where a measuring wheel might be useful and where it is not useful. What other tools can be used to measure distance?
Extensions or Modifications: Add a touch sensor to clear data to take a new measurement.
Use a touch sensor to trigger when measurements are displayed.
Add sound feedback when certain distances are reached.
Convert the device to a wench that measures the length of a string wrapped
around it
Reference 1
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Reference 6

LEGO Planet Rotation Structures





Name of Activity LEGO Planet Rotation Structures
Author STOMP
Keywords LEGO, ROVs, rotation, model, structure, planets, solar system
Subject NXT
Grade Level K, 1, 2, 3, 4, 5, 6
Time 1 Hour Total
Brief Description Students will assemble a rotating structure onto their pre-made LEGO ROVs.
Lesson Objectives: - To observe a model of planet rotation.
- To experiment with designing.
Materials Needed: Pre-organized LEGO kits
Pre-painted and labeled Styrofoam balls
Pre-made LEGO ROVs
Demonstration model with rotation structure
Preparation and Set Up: - Arrange students in groups of two.
- Distribute materials.
Necessary Background Vocabulary:
- Gears
- Bevel Gears
- Bushings
- Axles
  1. Students will work with the same partners as they did in “ROVing Away.”
  2. Review the solar system with the class.
  3. Tell the students that each group will be given a styrofoam planet.
  4. Each group will use a motor and gears, mounted on top of their rove, that will make the planet either revolve around the RCX or rotate around its axis.
  5. The styrofoam planet will be attached by sticking it onto a LEGO axle. That axle will be attached to a series of gears attached to the motor, through gears so that it rotates.
  6. Let students experiment with gears to create a planet that either revolves on it’s axis or revolves around the RCX.
  7. Tell students that they can change the speed of the revolutions by changing the gear structures.
    1. Ask students: what gear arrangement is faster? Which is slower?
    2. Ask students what speed is most appropriate for their planet.
  8. Come together as a class and let each group demonstrate their machine and how they used gears to achieve their goal.
Reference 1
Previous Activity (if applicable) Solar System Rotation and Revolution
Umbrella Unit/Curriculum (if applicable) Solar System

Solar System Rotation and Revolution





Name of Activity Solar System Rotation and Revolution
Author STOMP
Keywords model, solar system, rotation, orbits, sun, revolution, motion
Subject Non-LEGO
Grade Level K, 1, 2, 3
Time 2 Hours Total
Brief Description Students will create a working model of the solar system.
Lesson Objectives: To develop an understanding about planets rotating on their axes and their revolution around the sun within orbits.
Materials Needed: Video of the solar system
Large, teacher made diagram of the solar system
Teacher made planet info cards
Picture of the planet.
Distance and order from sun
Planet before and after it
Amount of time for one rotation
Four planet markers for each planet (picture and name of planet
Tape Measures
Preparation and Set Up: Make large solar system diagram.
Construct planet info cards.
Create planet markers.
Collect materials.
Arrange students into four groups.
Distribute materials to the class.
Necessary Background Use online resources to find information on planets. Try as a resource.



  1. Show students video on solar system. This video should include information about rotation and revolution.
  2. Talk about the meaning of rotation and revolution.
  3. Ask the students:
    1. How can you demonstrate the motions in the solar system?
  4. Break into groups and tell students that they can use anything in the classroom to aid their demonstration.
  5. Students will be allowed approximately 10 minutes to complete the task.
  6. Have each group present their demonstration.
  7. After the group demonstrations, explain to students that they will recreate a model of the solar system’s motions by using themselves as the sun and planets.
    1. Assign individuals, or small groups of individuals to be a specific planet, or the sun.
    2. Each group will be given a ball of string, four planet marker cards, and a planet info card that tells them the length of string they should cut to replicate their planets orbit.
    3. Bring the class to a large open area.
      1. You could clear the classroom by pushing desks to the side, go outside, use gymnasium or multi-purpose room.
    4. Decide where to place the sun first.
    5. The “Planet” groups will use tape measures to determine how far away from the sun they should stand. Students should place their markers at 4 spots with the same radius from the sun where their orbit will be.
    6. Have students place their strings to mark their orbits.
    7. Each student group will choose one member to stand on their orbit in a straight line from the sun.
    8. Using one student as an example show how the student would revolve around the sun while rotating on their axis.
    9. Have nine the students orbit the sun, each representing a planet.
  8. Have the class come together to discuss the difference between rotation and revolution. Students can write their explanations on a paper using words or diagrams.
Reference 1
Online Reference(s)
Umbrella Unit/Curriculum (if applicable) Solar System

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