Locker Puzzle (VIDEO!)

In this two-part video, students of St. Mark’s School first act out the famous locker puzzle:

100 lockers, all initially closed, lie along a corridor. Student 1 walks down the corridor and opens every locker. Then student 2 heads down and closes every second locker. Student 4 heads down next and changes the state of every third locker (closes it if is open, opens it if it is closed). She is followed by student 4 who changes every fourth locker, then student 5, student 6, and so on, all the way down to student 100 who touches every hundredth locker (namely, just the last one!).

What do the students see at the end of this result?

Video number 2 explains what we see in video number 1.

Video 1: The Demonstration
Video 2: The Explanation


    QUADRATICS, Permutations and Combinations, EXPLODING DOTS, and more!

    Written for educators - and their students too! - this website, slowly growing, takes all the content Tanton has developed in his books, videos, and workshops, and organizes it into short, self-contained, and complete, curriculum units proving that mathematics, at all points of the school curriculum, can be joyous, fresh, innovative, rich, deep-thinking, and devoid of any rote doing! Let's teach generations of students to be self-reliant thinkers, willing to flail and to use their common sense to "nut their way" through challenges, to assess and judge results, and to adjust actions to find success. (Great life skills!)


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