Step through an accumulator pattern on board to make clear how variables change within a while loop to help students understand this confusing topic.

  • Activity:
  • Show students the following code:
    • int i = 1; double result = 1; while (i < 9){ result = result + i; i = i + 2; }
  • Tell students you’re going to trace the value of i during the loop execution.
  • Draw a table on the board that will show the current value for i and result.
  • Cross out each row in the table as the code iterates to make it clear to students that the previous values are no longer available.
    • The table should look like the table below:
      • resulti
        1.01
        2.03
        5.05
        10.07
        17.09

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    External Source

    Interview with Serita Nelesen