Lesson Plan: The Wobble-Bot Rescue Mission

Materials Needed:

• Computer with the game Wobbledogs installed
• Lego Education Spike Prime set
• Art of Problem Solving (AoPS) Pre-Algebra or Introduction to Algebra textbook (for reference)
• Notebook, pencil, and calculator
• Measuring tape or ruler
• A small, stable object to act as "Wobbledog food" (e.g., a Lego brick, a small snack)
• A shelf or elevated surface (like a stack of books)

1. Learning Objectives (The Goal of Our Mission)

By the end of this lesson, you will be able to:

• Apply the Pythagorean theorem to calculate a necessary distance in a real-world scenario.
• Design and build a functional Lego Spike Prime robot with a specific purpose (an extending arm).
• Program your robot to perform a task based on your mathematical calculations.
• Explain how your mathematical calculations, engineering design, and programming code all work together to solve a problem.

2. Alignment with Standards (The "Why" Behind the Fun)

• Math (Common Core Geometry - HSG.SRT.C.8): You'll be using the Pythagorean Theorem to solve a practical, applied problem. This moves the formula from the textbook page into the physical world.
• Technology & Engineering (ISTE Standards for Students): You'll act as an Innovative Designer by using a design process to create a functional prototype, and as a Computational Thinker by developing and testing a program to accomplish a goal.

Lesson Activities

Part 1: The Mission Briefing & The Calculation (15-20 minutes)

The Scenario: Oh no! Your favorite Wobbledog is hungry, and its special treat is stuck on a high shelf. It can't reach it! We need to build a robotic arm to retrieve the treat and save the day.

1. Set the Scene: Place your "Wobbledog food" on a shelf or a stack of books. Place the Spike Prime Hub on the floor or a table some distance away from the base of the shelf.
2. Identify the Triangle: Look at the setup. The floor, the wall/books, and the direct line from the robot hub to the food form a right triangle!
   • Leg 'a': The distance along the floor from your robot's starting point to the base of the shelf.
   • Leg 'b': The height from the floor up to the "food."
   • Hypotenuse 'c': The direct-line distance your robotic arm needs to travel from the hub to the food.
3. Measure and Calculate: Use your measuring tape to find the lengths of Leg 'a' and Leg 'b'. Now, use the Pythagorean theorem (a² + b² = c²) to calculate the exact length your robotic arm needs to be. Write down your measurements and your final calculation for 'c' in your notebook. This number is your primary goal for the robot build.

Part 2: The Engineering Phase - Build the Wobble-Bot Arm (45-60 minutes)

Now that you have your target length ('c'), it's time to build! Your challenge is to design and build a robot using the Spike Prime set that can extend an arm to the length you calculated.

• Brainstorm: How can you make an arm extend? Think about using gears to push a long beam forward, or creating a hinged arm that unfolds. There is no single right answer! Sketch a couple of ideas in your notebook.
• Build Your Prototype: Choose your best idea and start building. Attach at least one motor that will power the arm's movement. Your goal is to create a mechanism that can accurately reach the target distance. Don't worry about perfection on the first try; engineers build, test, and rebuild all the time.
• Refine: Does the arm wobble too much? Add support beams. Is it not reaching far enough? Re-think your gear system. This is the creative problem-solving part of the mission!

Part 3: The Programming Phase - Bring Your Bot to Life (20-30 minutes)

A great robot is nothing without great code. Now, you will program the Spike Prime Hub to control the arm you built.

1. Connect and Code: Open the Lego Spike Prime app and connect to your hub.
2. Create a Simple Program: Your basic goal is to make the motor run long enough to extend the arm to the target, pause, and then run in reverse to bring it back.
   • Start with a "When Program Starts" block.
   • Use a motor block (like "Run for Rotations" or "Run for Seconds") to control the extension. You will need to experiment to see how many rotations it takes to reach your calculated length 'c'. This is a great mini-experiment in itself!
   • Add a "Wait" block to simulate grabbing the food.
   • Use another motor block to run the motor in reverse to retract the arm.
3. Test and Debug: Run your program. Did it work? Did the arm go too far? Not far enough? Adjust the numbers in your code (rotations, seconds, power) until it works perfectly. This is called debugging and is a key part of programming.

Part 4: The Final Test - The Rescue! (5 minutes)

It's time for the final mission test. Place your robot in its starting position. Place the "food" on the shelf. Run your final program.

Did the Wobble-Bot successfully retrieve the treat? Mission Accomplished!

Assessment (How We Know We Succeeded)

Your success is measured by the outcome of the mission:

• Show Your Work: Explain your Pythagorean theorem calculation from Part 1. How did you get your number for the hypotenuse?
• Explain Your Design: Describe your robot arm. Why did you choose that specific design? What was the hardest part to build?
• Demonstrate the Solution: The final, successful run of your robot is the ultimate proof that your math, engineering, and programming worked together to solve the problem.

Differentiation & Extension (Level Up the Challenge)

• For Extra Support: If the building is tricky, look for inspiration online for "Lego extending arm" designs. If the programming is confusing, focus only on making the motor run forward and backward, without worrying about the exact distance at first.
• For an Advanced Challenge:
  • Add Sensors: Can you use the Distance Sensor to make the arm automatically stop when it gets close to the wall?
  • Add a Claw: Build a functioning claw with a second motor to actually grab the "food" and hold onto it.
  • Introduce Trigonometry: Instead of just calculating the length, calculate the angle your arm would need to be at. Can you build a robot that lifts its arm to the correct angle before extending? (Hint: SOH CAH TOA).
  • Go Autonomous: Use the color sensor and some taped lines on the floor to make your robot navigate to the shelf on its own before extending its arm.