1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

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.

    Attached Files:

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


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    7 * 13 feet is approximately 28 meters.

    - Warren
  4. Dec 29, 2006 #3
    This is a parody of a video circulating around the internet that involves some “funny math”:

    http://video.google.com/videoplay?docid=4241480654150026320&q=funny+math&hl=en [Broken]
    Last edited by a moderator: May 2, 2017
  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
    Yeah, that's exactly what I thought had been done!
    Last edited by a moderator: May 2, 2017
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook