Why does playing monopoly take so long

It depends. When translating between prose (or "natural language") and mathematical expression, you need to be very specific about the meaning of your sentence, for someone else to express it correctly as a mathematic expression. Natural language (whether English or any other) allows for a great deal more ambiguity of meaning than symbolic language (whether chemical, mathematic, computer programming, etc). The way you worded this question, I am not sure whether you are studying the game monopoly itself as it is played (see 1 and 2 below) or whether the playing of monopoly is some kind of variable in a broader experimental context (see number 3 below). Here are three possible answers: 1. "Playing the game monopoly" can be a discrete variable if you measure the progress or duration of the game as a discrete number of turns. 2. "Playing the game monopoly" can be a continuous variable if you measure the progress or duration of the game by the passage of time. 3. If "playing the game of monopoly" is an attribute of one person or one class of people in a study, then it might be a simple attribute-- a constant-- and not a variable at all. (the word "playing" is present-progressive, so if there are no other modifiers specifying a period during which "playing monopoly" occurs, then you can assume the action is constant over the entire course of time you are examining.) If it is a variable attribute, then of course the answer depends on whether you are looking at how long Monopoly was being played (continuous variable) or how many times it was played (discrete variable).