It's a highly unlikely scenario to be in 10 galleries at one time. However, I'll play along... If the edition was 10, each gallery would get 1 of that image. 1/10, 2/10, etc. If your talking about hanging 10 different images, it may make sense to give each gallery the same edition number, mostly because it would be easier to keep track. That's not a scam. A scam would be to claim the edition was 10, but making 20 (having 2 number 1's, etc.). A scam would be to claim an edition is 10, but falsely claiming that numbers 1-6 have been sold when, in fact, they never existed.