Be a Storyteller Chapter Notes | Year 3 Computing IGCSE (Cambridge) - Class 3 PDF Download

Creating stories

• In this unit, students will create and modify programs in Scratch to tell stories, focusing on logical thinking and program design.
• Students will learn:
  • About logical thinking: Using structured reasoning to break down problems and create effective algorithms.
  • How to create programs with static objects: Including sprites that do not require code, serving as background or passive elements.
  • How to change code: Modifying code to achieve desired outcomes, such as adjusting movement or timing.

Algorithm to code

Logical thinking

• Algorithms are created to solve problems or perform tasks by providing a clear sequence of instructions.
• Writing an algorithm requires understanding the problem and devising a logical solution.
• Logical thinkinginvolves:
  • Breaking down a problem into smaller, manageable parts.
  • Analyzing each part to determine the necessary steps to achieve the desired result.
  • Arranging the steps in a sensible order to ensure the solution is effective.
• Example: Algorithm to make pancakes, using logical thinking to organize steps:
  • Steps identified:
    • Measuring out 1 cup of pancake mix.
    • Measuring out 1 cup of water.
    • Mixing all the ingredients together.
    • Adding extra water if the mixture is too thick.
    • Pouring the mixture into a heated pan.
    • Flipping and cooking the pancakes.
  • Ordered algorithm:

    Step	Instruction
    1	Measure out 1 cup of pancake mix
    2	Measure out 1 cup of water
    3	Mix all the ingredients together
    4	Add extra water if the mixture is too thick
    5	Pour the mixture into the heated pan
    6	Flip and cook the pancakes

• Logical thinking ensures the steps are sequenced correctly to achieve the task efficiently.
• Keyword:
  • Logical thinking: The process of understanding a problem and devising a solution that is structured and sensible.

Creating programs

• Scratch programs can include multiple characters or objects, some of which may not require code.
• Static objects:Sprites that do not move or change, serving as background elements or passive objects in a story.
  • Example: A radio in a story that does not move or interact but is part of the scene.
• Programs can combine characters with code (active sprites) and static objects to create interactive stories.
• Example: Developing a program for a story where a girl (Anina Dance) walks to a radio and turns it on.
  • Story requirements:
    • The girl moves right when the space key is pressed.
    • When the girl touches the radio, music plays.
  • Algorithm for Anina Dance (Part 1):

    Step	Instruction
    1	When the Green flag is clicked
    2	Say “A radio!” for 2 seconds
    3	Wait until touching Radio
    4	Switch to next costume
    5	Start Dance Celebrate sound

  • Algorithm for Anina Dance (Part 2):

    Step	Instruction
    1	When space key is pressed
    2	Move 20 steps

  • Implementation in Scratch:
    • Create a new Scratch project.
    • Add the Room 2 backdrop.
    • Add the Anina Dance and Radio sprites.
    • Position the sprites appropriately.
    • Add code to Anina Dance based on the algorithm, using blocks from the Events, Looks, Control, Sensing, and Sound groups.
    • The Radio sprite is a static object with no code, serving as a target for interaction.
• Keyword:
  • Static objects: Sprites in a Scratch program that do not have any code and remain unchanged during execution.

Making changes to code

• Modifying code allows programmers to adjust program behavior to achieve different outcomes.
• Example: Changing the "Move" block in Scratch:
  • Changing from "move 150 steps" to "move 300 steps" makes a sprite move twice as far.
  • This adjustment alters the sprite’s final position without changing other aspects of the program.
• Other adjustable coding blocks include:
  • "Wait () seconds" to change timing.
  • "Say () for () seconds" to modify dialogue duration or content.
  • "Switch costume to" to change a sprite’s appearance.
• Example: Creating a Birthday Story in Scratch:
  • Setup:
    • Create a new Scratch project with the Party backdrop.
    • Add the Princess, Cake, and Balloon1 sprites.
  • Algorithm for Cake (Part 1):

    Step	Instruction
    1	When the Green flag is clicked
    2	Switch costume to cake-a

  • Algorithm for Cake (Part 2):

    Step	Instruction
    1	When this sprite is clicked
    2	Switch costume to cake-b

  • Implementation:
    • Add code to the Cake sprite to switch costumes as per the algorithm.
    • Add code to the Balloon1 sprite to change costumes, with a potential modification to double the time taken for costume changes.
    • Test the program by clicking the Green flag and adjust the "wait" block in the Balloon1 code to achieve the desired timing.

Did you know?

• Storyboards are useful tools for planning stories in Scratch.
• Storyboard characteristics:
  • Show examples of the intended story elements before coding begins.
  • Help organize the sequence of events, characters, and interactions in a story.
  • Allow planning of backdrops, sprite actions, and dialogue without writing code initially.

What can you do?

• Use logical thinking to create algorithms by breaking down problems and ordering steps effectively.
• Create Scratch programs that include static objects to enhance storytelling without requiring additional code.
• Modify code in Scratch to achieve desired results, such as adjusting movement, timing, or sprite appearances.