I feel the following sentence unnatural.
#1"He has three times the number of my books."
Because my books don't belong to him.
This is sometimes used instead of the following in Japan.
#2 "He has three times as many books as I have."
I think #3 is natural.
#3"He has three times the number of books that I have."
What do you think about #1 and #3?
While none of them is technically wrong, I agree that #1 sounds unnatural. #3 sounds a bit off; I simply wouldn't use the word "number" in this context, although again, it's not wrong. #2 sounds perfectly natural and is the way I would express this,
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While none of them is technically wrong, I agree that #1 sounds unnatural. #3 sounds a bit off; I simply wouldn't use the word "number" in this context, although again, it's not wrong. #2 sounds perfectly natural and is the way I would express this,
I think that He has books as much as three times the number of my books is the best solution.
1-3 doesn't sound good to me.
The sentence that is the most idiomatic is #2.
He has three times as many books as I have.
CJ