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A Different Sort of Arithmetic

  1. Dec 28, 2006 #1
    There's construction going on in my university, and I found some fascinating figures written on one of the walls (presumably by the construction workers). It looked like someone had gone to a lot of trouble to prove that 7*13=28. Actually, assuming you can play mix 'n' match with units and tens, it's quite convincing! But it's driving me nuts. Can someone look at the attatched thumbnail and tell me what's really going on?

    EDIT: the "figure 1" "figure 2" "figure 3" are my own additions.

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    Last edited: Dec 28, 2006
  2. jcsd
  3. Dec 28, 2006 #2


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    7 * 13 feet is approximately 28 meters.

    - Warren
  4. Dec 29, 2006 #3
  5. Dec 30, 2006 #4
    Thanks! (I will now be able to walk into the lobby without fearing for my life...)
  6. Dec 30, 2006 #5
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