"The maximum number": plural or singular?

Kindly, what are your thoughts on the following sentences:

1. The maximum number of wordbooks (%d) have been saved.


2. The maximum number of wordbooks (%d) has been saved.

My opinion is that (1) is more appropriate as "save" relates to wordbooks (a plural noun) and "The ... number" is some kind of determiner.

The dissenting opinion is that "The number" is obviously singular, and the "wordbooks" are subsidiary.

I agree that (2) is grammatically correct but I maintain it implies merely a single number was saved, not the wordbooks themselves.

Answer

As explained in ‘The Cambridge Guide to English Usage, when number of is preceded by the, it is the head (the most important word) of the phrase ‘the number of . . .’ It is singular, and so requires a singular verb.

The case is different when number of is preceded by a. Then, it is a pre-modifying element, leaving the number of the verb to determined by the number of the following head word (wordbooks in your example), which will invariably be plural.