Harry's Grigott's Vault Number

[Phyllis]

David wrote:
 
<<Not having POA, I can't check, but did Sirius mention that his vault 
was next to the Potters'?>>

I can't recall Sirius ever saying that - he only mentions his vault 
number at the end of PoA in the context of explaining where Harry's 
Firebolt came from, but there isn't a reference there as to where his 
vault is in relation to the Potters'.  The weird thing is, the math in 
the problem works if you use 710 (which would be next to Sirius' 711), 
but the even weirder thing is that Scholastic, in their infinite (lack 
of) wisdom, edited out Sirius' vault number in the US version of PoA.  
So since the question was posed on a Scholastic site, it would be 
strange for them to require information that can only be found in the 
UK version of the books in order to answer the question.

Even odder still is that most of the people who answered the question 
did so correctly.

I am truly stumped.

Pippin, I will look forward to seeing you at Lumos!

~Phyllis
who apologizes for misspelling "Gringotts" twice in her original post -
eeek!