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  Lesson 13 - variables, position, rotation style  

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Lesson 13 Tasks

  1. A variable is a like a box that holds a changeable thing.
  2. Variable tiles have a left-pointing white arrow and a value.
  3. The x variable shows how far from the left a sketch is.
  4. The y variable shows how far from the bottom a sketch is.
  5. The heading variable shows how much the sketch is rotated.
  6. To set a variable in a script, drag its white arrow and drop it.
  7. Start a sketch from the same place, drag its x, y, and heading to startOver.
  8. Never put a tile after "pause script" in a startOver script.
  9. A bug is something that goes wrong in a computer program.
  10. Most of the answers are in the viewer.
  11. Hold the pointer over a tile will show balloon help for the tile.
  12. It's good to explore the viewer and the rest of Etoys.
  13. The rotation style variable in "graphics" tells a sketch how to bounce.

Starfish Challenge

Make a "hermit crab race" where at least three crabs start at the center of
a circle and each race to be the first to cross the line of the circle.
Make each crab walk in a different direction at a different speed.
Put the starting position and heading for each crab in the crab's
startOver script, so that they always start at the same spot.