Just curious... what exactly makes up the box office tallys? If a film makes $50,000,000 in a weekend, is that the total gross of all theaters, or is that money that the studios get?

For example, some theaters charge $7 for a ticket, and others charge $13 for the same film. Is a box office gross the total of all ticket sales, or just the total amout of cash the distributor gets?

And while we're on this topic, is there a set price per ticket that goes into the distributor's pocket or does that, too, depend on the theater?

The number is the total ticket takings.

The studio takes a percentage of that, which changes the longer it is kept in the cinema. I understand the big studios generally get up to 80% of the takings from the first weekend which can gradually drop to about half.

Cinemas often make more than half of their income from drinks and snack sales, getting this right is the make or break of most theaters.