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How can I tell how many four sided shapes are here?

  1. Aug 24, 2006 #1


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    How can I tell how many four sided shapes are here? Counting seems so... not what a smart person would do.
  2. jcsd
  3. Aug 24, 2006 #2


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    I just see one - a box with a red X in it.

    And, yes, counting does seem like overkill for one object, especially when the average person can discriminate between four objects. I don't start counting until there's at least five objects.

    On the other hand, if the person behind you in the express lane asks you if you know how to count because you had 13 objects instead of 12, it's always good to give her an easy challenge when you hold up a finger and reply, "Yes, can you?"
    Last edited: Aug 24, 2006
  4. Aug 24, 2006 #3
    BobG, copy and paste the link into your address bar.
  5. Aug 24, 2006 #4


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    Unless I've made some silly omission, total = C(4,2) + C(5,2) + 4 + C(3,2) + 1 = 6 + 10 + 4 + 3 + 1 = 24

    Does that count as "counting"?
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