Let’s continue celebrating winter by building sleds for Sphero robots to drive through last week’s wintery town!

Our goals this week are to explore the engineering design process while making sleds and bridges, and learn about angles and coding to program Sphero robots.

Activity 1: Sleds for Sphero Activity 2: Programming the Spheros Activity 3: Build a Bridge
  • 1 Sphero robot per group of students
  • Scissors
  • 1 Solo cup per group
  • X-Acto knives/ box cutters (for adult use only)
  • 2 straws per group
  • Tape
  • Marbles (many)
  • Paper/Cardstock
  • Writing/ coloring implements
  • 1 Sphero robot per group of students
  • 1 Kindle with Sphero Edu installed per group
  • Tape
  • A board/ large paper
  • 1 Sphero robot per group of students
  • 1 Kindle with Sphero Edu installed per group
  • Blue plastic bags (to act as a “river”)
  • Craft sticks
  • Pipe cleaners
  • String
  • Marbles (many)
  • Glue (optionally hot glue)
  • Tape
  • Scissors
Lesson Flow
  1. Charge Spheros and Kindles
  2. Gather materials
  3. Introduce the challenge: Build a sled that Sphero can pull
  4. Show example photo of Sphero sled
  5. Have students build a sled in teams out of 1 Solo cup, 2 straws, and tape
  6. Test the sled
  7. Revise design if necessary
  1. Charge Spheros and Kindles
  2. Show students how to program in Sphero Edu
  3. Have students test their sleds/ explore how to program
  4. Drive working sleds around the wintery town!
  1. Charge Spheros and Kindles
  2. Gather materials
  3. Introduce the challenge: Build a bridge that can support Sphero and its sled
  4. Have students build their bridges in groups
  5. Test by driving the Spheros over the bridge
  6. Revise bridge design if necessary
  • Explore the design process
  • Fulfill criteria while staying within constraints
  • Explore iteration and “productive failure”
  • Learn coding and computational/ sequential thinking
  • Learn about angles/heading
  • Explore the design process
  • Fulfill criteria while staying within constraints
  • Explore iteration and “productive failure”
  • Learn about how to support weight

Lesson Steps

  1. Charge Spheros and Kindles. Be ready to program the Spheros (see tab for Activity 2) on the first day for any groups that finish their sleds before the first session ends.
  2. Break the students into teams. You should only have as many teams as there are Spheros.
  3. Introduce the challenge: In your team, build a sled that Sphero can pull using only 1 Solo cup, 2 straws, and tape (decorations optional).
  4. Show this example photo of a Sphero sled:

Similar to the Christmas tree challenge last week, only show the picture; don’t make an example. Let the picture spark their imaginations. Tell students that they can make their sled like the picture, or any other way they want, as long as they only use the materials given.

5. Have teams build their sleds.

6. Place Sphero in the sled contraption. Use a short program (see Activity 2) to drive Sphero around a bit to see if the sled stays together.

7. If not, then iterate! Revise the design until it is structurally sound.

8. Test how many marbles the sled can successfully pull. If it falls apart with any less than 5 marbles, revise the design to be stronger. See which team’s sled can pull the most marbles!

Today we will use the Sphero to learn programming. 


  1. Understand the angles of a circle (0, 90, 180, 270, 360).
  2. Understand how robot heading will change the way the robot drives.
  3. Learn how to start your program by aiming the Sphero.
  4. Utilize sequential thinking in order to think through the steps. 

In preparation

  • Gather materials: the Spheros and Kindles! (and make sure everything is charged!)
  • Make sure Sphero Edu is downloaded on your Kindles. 
  • Each Kindle will need to be connected to a device simply by selecting a Sphero and it will light up (you can see one example of that HERE at approximately 1:15).
  • Print out (or write) the numbers 0, 90, 180, 270, and 360 and tape those numbers on the walls in their proper positions around the circle.
  • Put a “start here” space on the floor (use tape or a paper).
  • Download the Sphero app on your computer so you can also show it on the big screen as you start the lesson. Note that it seems that, if you don’t have a Sphero connected, you can only open the program editor from the computer app if you click on a preexisting program.


  1. If you have not already, arrange your gingerbread buildings from last week into a “town” that the Spheros can drive through.
  2. Before you pass out the Sphero robots to everyone, show the kids your robot and let them make some predictions.
    • Which direction will the robot go if you told it to go forward? 
    • What is the front of the robot?
    • How fast will the robot go?
  3. Pull up the programming language on your device so that everyone can see. Show them how to AIM the robot so that you know which direction it will head in. (video HERE)
  4. Then pull up the coding language and pull up a block:The “on start program” is there by default. The movement block is under the “Movements” category.
  5. Have students give explanations for each part of this block (roll, speed, and duration), then explain what each will do to the robot. 
    • Direction – look at the signs on the walls! No matter what direction the robot is in (if started in the same place) it will roll towards the marked wall of 90 when you put 90, 270 when you put 270 and so on. This is called heading.
    • Speed- this is how fast the robot will go. Do you think it will go faster or slower if we put it at a slower speed?
    • Duration – This is how long it will move. Bigger times equal longer distances. 
  6. Demonstrate by connecting two blocks and letting them predict which way the robot will run before running the code and trying it.
  7. While there are lots of blocks to explore with Sphero, I would stop talking here and pass out the Spheros and let them explore. Don’t forget to tell them how the robot will need to start in the same place with the same AIM each time. They will continue to add more blocks as their program gets bigger.
  8. Remind them that they need to program the Spheros properly or they could run into and even destroy the cardboard buildings!

Common problems:

  • “Robot isn’t doing what I tell it to” – usually it’s doing exactly what they tell it to; it’s not doing what they expect it to. Ask them to explain what they want it to do. Then help them break it down—this is part of learning sequential thinking. Before they push run, ask them what they think the robot will do. If they are right, then they are starting to understand sequential thinking. 
    • As a follow up, if students are really struggling with this, ask them to write 2-3 steps of what they want so you can help them to make that in coding.
  • Students may delete each block and just run one block at a time – continue to reiterate that you will build blocks together to make a longer path for your robot
  • Students will put in lots of code before they test – remind them in the beginning to only put 1-3 blocks before they test and see if that’s what they want before they continue.

Next Steps:

  • Don’t let them spend so long exploring that they get bored or frustrated. When enough people have started to understand, watch THIS VIDEO or talk about coding on your screen some more, and then have them use the Sphero to make a square or go through a maze, preferably made out of the gingerbread buildings from last week.
    • Having a goal where they can feel success is really important for learning. 

If students finish the square or finish running their Sphero sleds through the gingerbread town:

  • There are tons of extension activities HERE 
  • I would often have students draw a letter and then see if I can guess the letter


Students could use the Sphero Play app to have Sphero act as a remote control car—just drive it. I would not have students use things that way until after they have tried programming it or they will not put in the work to learn how to program it. However, for the bridge challenge the Play app might be needed.


Build a “river” on the outer edge of your winter town. One easy way to do this is to tape together several blue plastic grocery bags.

Tape down upside-down Solo cups to the floor on either side of your river, 4 per group. These will be the “towers” on which the bridges will rest. Each pair of cups facing each other across the river should be at least 1 foot apart (i.e., your river should be at least 1 foot wide). The two cups on the same side of the river should be far enough apart that the Spheros+sleds should fit between them.

Also, don’t forget to charge up the Kindles and Spheros!

Lesson Steps:

  1. Introduce the challenge: In teams, build a bridge that can support Sphero and its sled using only the materials provided: craft sticks, straws, string, pipe cleaners, and tape/glue. The bridges will go on top of the Solo cups. Teams will also need to build the ramps up to and down from the Solo cups.
  2. Show pictures of different types of real-life bridges (see pictures at the bottom of this page). Have each team choose a bridge type to emulate in their design.
  3. Have students build their bridges in their groups.
  4. Test by driving the Spheros with their sleds over the bridge. If the bridge breaks, iterate! Revise the design and try again.
  5. Extension challenge: See how many marbles the Sphero sleds can pull over the bridge. Alternatively, simply put a cup on each bridge and fill with 1 marble at a time, until the bridge collapses.