Build a Parsons problem

What students should learn

Students can see how a working program fits together: set up a variable, repeat the work, then print after the loop.

Use a program students have already seen, with four real lines and one believable wrong line. The example below adds 1, 2, and 3, then prints 6.

A teaching sequence

1. Take typing out of it. Give total = 0, the loop header, total += n, and print(total) as separate lines. Students put them in order, then explain the result.
2. Make indentation part of the task. Turn on indentation in the Ordering block. In the solution, total += n is inside the loop and print(total) is outside it. Ask what changes if print moves inside.
3. Add one wrong line. Add total = n as an extra line that doesn’t belong. Ask students why it gives a different result than total += n. Skip distractors that are just typos.

What to assess

Save the correct order and indentation as the solution, then preview it as a student. Try a correct answer, a misplaced print, and the wrong line to make sure each is graded the way you expect. Add a short explanation question if you want to know why students chose that order.

A follow-up task

Next, take away the lines and ask students to write a similar program. If a student has trouble dragging, agree on another way for them to give the ordered, indented answer before you grade it.

Build it in your course