First, I try to decipher the probelm by creating a table with the locker numbers and the student numbers up to 10. By the time I finish the number 10, I can start to see a pattern.
Numbers 1, 4, 9 have CLOSED lockers, and they are perfect square numbers.
Numbers 2, 3,5,6,7,8,10 have OPEN lockers. I can see that 2,3,5,7 are prime numbers, and 6,8,10 are even numbers. I begin to wonder what is in common between these two sets of numbers. Then, I notice that they both have even number of factors. As I go back to look at the Prime numbers, I notice that they have odd number of factors. From there, I can conclude that, locker numbers with odd number of factors are CLOSED, and locker numbers with even number of factors are OPEN.
Note that the first locker is remains CLOSED.
Very nice, Sukie! I'm glad you asked why the square numbers too...
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