I ordered a Shakespeare book for my daughter's college class. I was very careful to match the ISBN that she was given. The book just arrived, and I first thought I had a RWP. The ISBN didn't match. So I checked my account page, and I had ordered the 13 digit ISBN. The same book had a 10 digit ISBN listed also. So, I marked it received. No problem with the order. What I'm wondering is, since there's no 13 digit ISBN anywhere in the book, will this for sure be the exact same book? I'd hate for my daughter to have a problem at the last minute, and maybe not even know til it's too late. 

I don't really know much about ISBNs, so I guess I'm looking for reassurance. 

Thanks. :)

Same book (title & author), just a different cover?  PBS does not require the cover picture to match, only title, author, binding, and ISBN.  The 10 and 13 digit ISBN's are tied to each other, and I've never seen one assigned to a book and the other for a different book (should be impossible due to a cross check system).

But...some books (especially classics) will have several print runs (often with different covers) under the same ISBN.  Should be the same edition, but makes it difficult to tell if you are receiving a newer copy or one 30 years old with brittle glue

Denise is correct that the 10 and 13 digit ISBNs are unique to each other -- if the 10 digit matches, the 13 should match as well.

If it helps, there are tools online to "convert" a 10 into a 13 or vice-versa, so you could use it to ensure you've got the right one.  Here's one: http://www.isbn.org/converterpub.asp

Thanks, y'all. I'm comforted, then. It's old and yellow, but most of those kind are. That's not a problem. I normally don't care about the ISBN when I order, but some professors can be persnickety. ;)