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Computational Thinking II

Ovals, boxes and diamonds

A flowchart is a plan drawn as shapes joined by arrows. Here is a plan for a monsoon morning.

Start: an oval.
Step 1 of 5
  1. Start: an oval.
  2. One step: a box.
  3. One question: a diamond.
  4. Yes goes one way. No goes the other.
  5. A cloudy morning takes Yes.

The rule

Every shape has a fixed job. A box does one step. A yes-or-no diamond asks one question, with two ways out.

A way out is an arrow that leaves the shape. Fixed jobs let anyone read a chart the same way.

Four flowchart shapes
ShapeIts job
OvalStart or end
BoxDo one step
DiamondAsk a question. Yes or No.
Slanted boxInput or output

A slanted box takes a value in (input) or shows one (output).

Name the shape for each card. Then pick the arrow.

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This track

  1. 0 Start here
  2. 1 Steps written, steps taken
  3. 2 Look at the middle
  4. 3 Ovals, boxes and diamonds
  5. 4 Give every case an answer
  6. 5 Predict, run, compare
  7. 6 The big picture
  8. 7 Track quiz

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