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Halloween Lesson - Catch the Potion

45 Minutes

Lesson Overview

Students will create a Halloween themed game where they control a sprite on the screen using Marty’s arm force sensors to catch the falling potion. They will require to use their knowledge about the force sensors, loops, functions and if statements to complete the game.

Key vocabulary:
    Force Sensor, Sprites, Function, If Statement, Broadcasting,

Content Sections

  • Learning Objectives
  • Extensions & Challenges
    • Additional Reading
    • Halloween Lesson - Catch the Potion

      45 Minutes

      Lesson Overview

      Students will create a Halloween themed game where they control a sprite on the screen using Marty’s arm force sensors to catch the falling potion. They will require to use their knowledge about the force sensors, loops, functions and if statements to complete the game.

      Key vocabulary:
        Force Sensor, Sprites, Function, If Statement, Broadcasting,
      • Lesson 1.17
      • Laptop, PC or Tablet
      • Technologies/Arts/Literacy/Numeracy
        • Marty the Robot
        • Access to compatible devices connected to Marty on Scratch

      Learning Objectives

      • Describe the value that is returned from force sensors in Marty’s arms
      • Describe how and when to use functions
      • Describe how if statements work
      • Explain how hardware and software interact

      1. Discuss with the class what the sensors are on Marty’s arms and how they work (if students have not completed the handshake lesson then this will need to be introduced!)

      2. Introduction that we are going to use the force sensors on Marty’s arms to move a sprite in Scratch to catch falling potion

      3. In small groups, students should connect their device to Marty on Scratch 3 and add in appropriate stage background graphics and one sprite that will be moving around to catch the falling option

      4. Students should begin to experiment with getting back the values from the force sensors and when this value hits the minimum value (usually 3) then the sprite should move accordingly - beware that if Marty is facing towards students they will have to code the sprite to move in the opposite direction

      5. Once students have the sprite on the stage moving left and right based on the arm being pushed down on Marty, it’s time to code the falling potion

      a. Add a new sprite (potion sprite is already available on Scratch but if students wish to design their own falling object then they can do this!)

      b. Code the sprite to fall down the stage from a random x coordinate (students will need to explore the coordinate system on the Scratch stage to decide which values are appropriate)

      6. In the students programs, they should make sure to measure both the y coordinate and whether the potion sprite has touched the sprite controlled by Marty so that they can code the potion to reset and begin falling from a different position

      7. When the potion and the sprite controlled by Marty touch then that means that we have caught the falling potion, students should keep track of the number of times that we catch the potion by using a score variable

      8. Encourage students to ask other groups to test out their game to make sure it fully works!

      Extensions & Support

      • Discuss with other student groups what makes the game easy and difficult - what changes could they make to their programs to make the game more difficult? (Technologies/Literacy)
      • Add an additional falling sprite that the player needs to avoid, it could be another potion that is a different colour or something completely different (Technologies)
      • Add a timer to the game and challenge the player to catch as many potions as they can within that time (Technologies/Numeracy)

      Additional Reading

      • Marty the Robot Educator Guide
      • Educator FAQ