The Nut Job: A Number of x The Number of

A number of should be used with a plural verb. Think of it this way: 

A number of equates to the word they.

Ex:

A number of fans buy tickets at the game. (They buy tickets.) 

A number of dogs in our neighborhood actually like the mailman. (They like the mailmam.)

On the other hand, when using the number of, use a singular verb. The number of equates to the word it.

Ex:

The number of snowstorms this year was more than expected. (It was more than expected.)

The number of dogs in our neighborhood has grown over the past several years. (It has grown.)

I.              Watch the movie segment and choose the best answer: