You get your prelim score by bowling on your console and taking 3 games scores dividing it by 3.
With Unified you add Athletes & Unified Partners score together after every game. and devide by 2. That is your games score as a team.
Example: (1st Game: 86 + 2nd Game: 78 + 3rd Game: 82) = 246 / 3 = Prelim Score: 82