[adrusi]

53 is pronounced "5 times 3", synonymous with "3, 5 times in sequence". So if the problem given had been presented as "5 times 3" I would agree that that means "3+3+3+3+3".

However, just becuase 53 is pronounced "5 times 3" doesn't mean that it's exactly the same thing. We pronounce it that way because it's convenient, "times" is a one syllable word that we can inject right where the multiplication sign goes, and have it be a meaningful, representative sentence. But that doesn't mean that "53" derives its semantics from "5 times 3". "53" is an abstract mathematical expression that has no concept of "grouping". It can't have a concept of grouping --- how would you extend grouping to something like matricies.

[jeremysmyth]

It's not pronounced that universally either.

I say "5 multiplied by 3", which informs my interpretation of which value is repeated by which. Another commenter uses the phrase "5 into 3".

When you use an less formal (and inherently ambiguous) language (English) to state a condition in a formal language (used to define multiplication), you're gonna have problems of this nature.