Agrocery store has a shelf with half gallon containers of milk . what type of number best represents the total number of gallons

Since the statement or type of number are not given or provided in the questionnaire. We answer the problem using the algebraic approach and hypothesizing and calculating the given vales hence,
Let:

N = containers of milk And since the shelf only has a half gallon containers of milk.

The equation shall be in the form of: N / 2 = total number of gallons N / 2 is in fractional form and the type of number indicates in form of a fraction kind.