Have students sort large signs their classmates hold to better visualize different sorting algorithms. However, be mindful of unsuitable factors to sort by, such as height and weight.

  • Background:
    • First explain the sorting algorithms you’ll cover to students.
    • Use examples on the whiteboard to show sorting methods.
    • Note: Use this activity before students start programming the sorting algorithms.
  • Activity Details:
    • Have 8 students stand at the front of the room each holding a number written on a piece of paper.
      • You could opt to sort by other factors instead of random numbers:
        • However, avoid sorting students by physical characteristics like height, age, or other factors since they might make them uncomfortable.
        • Instead you can use neutral topics such as birth date, birth month and mailbox numbers. 
    • Have students hold the paper with the number facing them so that no one can see it.
    • This prevents the sorter from taking short cuts in sorting the list of numbers.
    • Ask for another student volunteer to sort these numbers using a particular sorting algorithm.
    • This is where hiding the numbers becomes important because for each comparison of two numbers, they have to ask the students holding the numbers what their numbers are.
    • For a sorting algorithm like selection sort, once some of the numbers are sorted, you can have those numbers visible to the class.
  • Notes:
    • It is common for students to forget or skip over steps. This a great opportunity to reinforce the steps in the algorithm.
    • So that each student can practice sorting algorithms in their seat, use playing cards or dixie cups with numbers written on the bottom of the cup and give each student their own set of these items to sort.

More about this tip

External Source

Interview with Brandon R. Rodriguez

Interview with Janet Davis