According to box office estimates, An American Carol grossed $145,000  yesterday in 1,621 theaters for a per theater average of…. $89.

As BoxOfficeMojo explains:

Theaters refers to the number of locations where a movie is playing, but it does not reflect the number of screens. One theater location, for example, may play a movie on several screens—this is a necessary distinction since print and Web references routinely and mistakenly refer to theaters as screens.

So $89 is not per screen or per showing.  That is for the day, the whole day, no matter how many screens An American Carol appears upon. 

$89. Eighty-nine dollars. Ochenta y nueve dólares.

For the whole day.

The closest movie theater to my house  has showings at 1:00pm, 3:10pm, 5:20pm, 7:35pm, 9:45pm

You do the math.