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Intro to Coding
Lab 2 - Robot Treasure Hunt

Teacher Portal

Launch the Engage Section

ACTS is what the teacher will do and ASKS is how the teacher will facilitate.

  1. Introduce the activity treasure map activity by making a connection to the students’ experiences with scavenger hunts.
  2. Show the 123 Robot, Coder, and Coder cards.
  3. Show students a treasure map, and place the 123 Robot on the map.
  4. Break down the problem or challenge into smaller pieces. Challenge: move the 123 Robot from start to the treasure.
  5. Move towards the treasure.
  6. Introduce the vocabulary term sequence to the students as they talk about the order in which they inserted the cards into the Coder, and why the order is important.
  1. Ask the students if they have ever been part of a scavenger hunt. How about a maze? What were you trying to do? (Move around to find the treasure or prize). 
  2. Who remembers how to code the 123 Robot with the Coder and Coder cards? 
  3. Explain to the students that we will use the Coder cards to instruct the Robot to move around the map to find a treasure. 
  4. What are some Coder cards you can use to tell your 123 Robot how to move around the map? Examples: "Drive 1" or "Turn left." 
  5. Do you see that each Coder card is one action of the 123 Robot?
  6. What if I switched the cards around? Would the 123 Robot move in the same way?  Is the order of the instructions important?


  1. InstructInstruct students that they are going to use the Coder and Coder cards to make the 123 Robot to move around the map to find a treasure.
    • Ask students to show the class what they remember about using the 123 Robot. You may need to remind them of the steps for waking the 123 Robot by pushing the wheels along a surface until you hear the startup sound, as shown in the animation below. Turn on sound for this animation. For more information about the 123 Robot, see the Using the VEX 123 Robot VEX Library article.
    Video file
    • Students may also need a reminder on how to connect their 123 Robot to the Coder as shown here. To connect the 123 Robot, press and hold the Start and Stop buttons on the Coder, and the Left and Right buttons on the 123 Robot for at least 5 seconds, until you hear the connected sound, and the indicator lights flash in time, as shown in the animation below. Turn on sound for this animation. For more information about the Coder, see the Using the VEX 123 Coder VEX Library article.
    Video file
    • Show the treasure map and then place the 123 Robot on the map.

    Image of Treasure Map setup on 123 Tile Field
    Treasure Map Setup

    • Demonstrate how to decompose, or break down, the challenge of getting from start to the treasure into steps. Each step is a behavior represented by the Coder cards.  
      • See the "Steps for planning and sequencing Coder cards in a project" section in the Background information for a detailed breakdown of how you can demonstrate these steps. 
    • Create a project to  move part of the way towards the treasure, showing students the cards that you chose and how they result in a specific movement of the 123 Robot. You can create a project with the following cards to move part of the way to the treasure:

    Image of Project in the Coder that will move the 123 Robot part of the way to the treasure: When started, Drive 4
    Example Project to Move Part of the Way to Treasure

    • Ask students if the 123 Robot would move the same if you change the order of the Coder cards. No! The order of the cards is important.
    • Introduce the vocabulary term, sequence, to the students. Sequence is the order in which cards are executed one after the other. The order of the Coder cards is the order in which the 123 Robot will perform the behaviors. See the "How sequencing is used in this Unit" section of the background for more information.
  2. DistributeDistribute the 123 Robot, Coder, a "When start 123" Coder card, and set of Motion (blue) Coder cards. Each group should get one set of materials.
    • Limiting the number of cards will help students to focus on the challenge of navigating the map. See the Environmental Set Up section for a complete list of Coder cards suggested for this Lab.

    Image of Materials Needed: 123 Robot, Coder and Coder Cards
    Materials Needed

  3. FacilitateFacilitate a discussion about how to use the 123 Robot, Coder, and Coder cards. Remind students that they need to:
    • Push to wake  the 123 Robot.
    • Connect the Coder to the 123 Robot.
    • Insert Coder cards into the Coder
    • Press the Start button.
  4. OfferOffer suggestions for how groups can work together. Students will need to share treasure map areas. Tell groups to test their projects on the treasure map one at a time. After one group tests, they should talk about what they want to change in their project, and switch their Coder cards as needed. The next group can be testing their project during this time.
A VEX 123 character

Teacher Troubleshooting

Facilitation Strategies

  • During the environment set up, the teacher should have the treasure map set up on the 123 Field for each group before beginning the Lab. 
  • Remind students to watch the green indicator light on the Coder to monitor which card the 123 Robot is executing as it moves around the map. 
  • Remind students that the first Coder card always has to be "When start 123." For more information about Coder cards, see the VEX Coder Card Reference Guide VEX Library article.
  • The 123 Robot will not start a project until the start button is pressed on the coder, and that they cannot change the cards while the 123 Robot is moving.
  • Take turns - Throughout the Lab, students should take turns within their group,  During Play, alternate who inserts the Coder cards and who starts the project, and who places the 123 Robot on the map.
  • Use printables as manipulative to support project planning - See the printable resources available in the VEX Library, and use them with students as they are planning and building their Coder projects. You could use the motion planning sheets for students to draw the path they want their 123 Robot to travel, as well as the fill-in project and motion planning sheets for students to document their Coder cards and the path of the 123 Robot. You can also use the fill-in Coder sheet for students to write or draw their Coder cards to "save" their projects.
  • Use Coder card posters to reinforce learning with the Coder - Highlight specific Coder cards, or refer to cards as you are teaching with the Coder card posters. Students can use these posters to review terminology as they are working with VEX 123. See the Using Coder Cards Posters in the Classroom VEX Library article to access these printable posters and to see more strategies for using them in your learning environment.