Grid Coding

Objectives

• Create an algorithm that will successfully get a robot to a goal point within a grid while avoiding the obstacles.

• To objectively read an algorithm written by a classmate as a robot would.

Materials

• Green tape or masking tape

• Paper and pencil

• Obstacles or obstacle cards to place in a grid on the floor

• A goal to place in a grid square on the floor

• Lots of space!

• (Optional) A set of direction/arrow cards (these can be handmade) 

Key Questions

• What was the hardest part about writing the algorithm for your robot? 
• Why do we need break down the path through the grid into simple steps, given one at a time? 
• Is there more than one way to complete the goal? 
• What strategies could you use to debug your code? 

What To Do

1. Prepare direction/arrow cards if using them to communicate your algorithm. (You can also write down symbols on a piece of paper instead) 
2. Tape a grid on the floor. Designate a starting square, a goal square, and add a few obstacles to the grid as well.  
   • You can set up your grid to explore a variety of content areas here. For example, you could fill the grids with different numbers to help explore math concepts. You can fill the grid with story elements to help with storytelling. You can use whatever objects are relevant to a current topic you are teaching in your class and use the grid as a way to show your students’ learning.  
3. In partners, have your students write down their algorithms to navigate their “robot” partner through the grid. This can be done in a variety of ways: you could have direction cards that they lay out to code their robot or they can use symbols to write out their code. Encourage them to write out the entire code before their robot friend tests it out. 
4. Have them test out each other’s codes while walking through the grid. Invite them to reflect on the process. Did their robot interpret their code in an unexpected way? Were there any bugs in their code? How did they go about debugging them? 

Extensions

• In coding, we use a loop when we want to repeat some steps. Is there anywhere in your code you could add a loop? How would you represent that? 
• Challenge your students to find the most efficient code (i.e., least number of steps)  

Other Resources

Take your coding skills one step further and try programming a virtual robot to navigate a grid!  

• You can code a Bee Bot here: https://beebot.terrapinlogo.com/ 
• Help Gracie code a GoBot here: http://graciecodes.com/ 

Create your own challenges on the different mats available! 

To step it up even further, try and code a virtual Ozobot to correctly trace the shapes with 10 basic block coding challenges here: https://games.ozoblockly.com/shapetracer-basic