Use the "'build your own block'" feature in Scratch 2.0 to teach "bottom-up" or "top-down" processes for breaking up problems.

  • The "top-down process" involves "dividing a large program into modular pieces with a clear logical structure," essentially decomposing a problem.
  • The "bottom-up process" is a "way of building complex problems... [by] combining existing procedures," fundamentally composing a solution from already existing pieces.
  • The "'build your own block'" feature in Scratch provides a way for students to define simple procedures and helper functions that can then be called to create more complex procedures. For example, students can make a block that draws a petal/leaf which they can then use this block as a sub-routine in a script that draws an entire flower.

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