Tower Of Hanoi: Experiential Recursive Thinking
  • How to explain recursion?

Tower of Hanoi is one of the classic problems to look at if you want to learn recursion. It is good to understand how recursive solutions are arrived at.

Tower of Hanoi consists of three towers with n disks placed one over the other. The objective of the puzzle is to move the stack to another tower following these simple rules.

  1. Only one disk can be moved at a time.
  2. No disk can be placed on top of the smaller disk.

It is a method of solving problems that involves breaking a problem down into smaller and smaller sub problems until you get to a small enough problem that it can be solved trivially – if you look around you can find the use of recursion in a simple way like in the movie Inception- Leonardo had a dream, in that dream he had another dream, in that dream he had yet another dream, and that goes on.

Recursion is useful in solving problems which can be broken down into smaller problems of the same kind.

Here is another example that the simple concept of recursion can be applied to- the Russian nesting doll which is a set of wooden dolls of decreasing size placed one inside another.

Blossoms video:

Your assignment is to try and find a way to explain the concept of recursion.

Discuss your ideas with your teammates in the group; search the internet for information and inspiration, ask people around you, look for recursion in different cultures.

Try to come up with a model (such as a game) that from your perspective can explain the concept of recursion.

Provide an answer by clicking on "Map" and then on "Add an Answer".

Results, Analysis and Discussion

1.  Wu Qiling (14.08.2017 pm 03.00.04)
sincere assessment for Qiling


    I would like to thank you for presenting such an interesting question or we can say challenge about recursion.

    Your instruction is very clear. Besides, the scientific background and explanations about recursion are concise and understandable. Further, what I treasure most is your attempt to adapt the concept of recursion to different situations. This indeed shows the spirit of mathematicians.

    Your work is excellent; however, I still want to make some comments and recommendations:

  1. Because of my lack of knowledge in recursion, it takes time for me to figure out the question and the solution raised in the video. It would be more audience-friendly if the authors give more information about the background knowledge of recursion.
  2. The background knowledge mentions about Tower of Hanoi and Russian nesting doll. It would be more clear if the authors clarify them a little bit more.
  3. The process of thinking is important. My biggest concern is that the example video does not show the process of inquiring as the video focuses on the solution, which means there is little time for the audience to think of the question.  

  Thanks again for such an excellent work!

  Wu Qiling

2.  Wang Dayang (17.08.2017 am 01.23.40)
a few comments from Dayang Wang

This video is very good example of teaching recursion. 

  1、This structure gives a vivid explanation of recursion. 
  2、In the video, the process of moving disks is clearly showed. 

Apart from the many strength of this project, there are also some challenges. 

  1、The creators may make the video with more special effects to attract the           attention of the students. 
  2、In the video, disposal cups are used to represent disks, but maybe the authors can     used tools that are more similar to disks in appearance. 
  3、I think maybe this project can also add more fun to it. For example, there is a       story of moving 64 disks in a very big Hanoi, a question can be given to the students     like how long it may take for people move these 64 disks from one pillar to another. 

Thank you!



3.  Peleg Tomer (20.08.2017 pm 12.55.43)
peer assessment - tomer peleg

I really liked the idea of the movie, I believe that kids like riddles, and even more they like to solve riddles. The riddle you gave about saving the family describes well the idea of recursion, you did very well when you added the grandfather and showed the recursion step. I think that you could have explained more about this recursion step and ask at the end a question regarding this step, like “can you describe the recursion step ?” and then gradually add another person and after that 2 others and so on.

One small correction, in the rules of the Hanoi tower the first rule should be “only the most upper disk of the piles can be moved”

Thank you for your work and idea,


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