Continuity mistake: At the beach house, Finch is putting up his graduation photos of him, Stifler, and Stifler's mom. The top photo, Stifler's mom is not wearing the graduation cap, the bottom one, she is. Later, after Stifler's brother shows up and Finch is disappointed, he takes the pictures down but they have reversed their order. Stifler's mom with the cap is now on top. (01:00:12 - 01:16:45)
Continuity mistake: In the scene where Jim, Oz and Finch are sitting in front of Dog Years after the call from Nadia, you can see some people in the back. When Kevin shows up the people disappear. The camera moves away for a moment and after it comes back, the people have reappeared. (00:21:35)
Continuity mistake: In one of the first scenes of the movie when Stifler is talking to Oz in a classroom, you can see clearly that Stifler has a cold sore on his left side of the bottom lip. The camera changes to Oz and later on when shows Stifler again the sore is gone. (00:05:10)
Continuity mistake: At the beach house when Stiffler is passing out the porn, he throws Jim a porno movie that has a different title than the one that gets glued to his hand. (00:54:45 - 01:01:00)
Continuity mistake: In the scene where Jim makes a fool of himself by trying to play the trombone, he yells into the microphone and turns to Michelle ( who is sitting towards the left of the row of seats). He asks something like, "What should I do?" He then turns around and the camera cuts to a different angle. Now, he is standing in front of a girls that is two seats down from Michelle. (00:32:40)
Continuity mistake: When Jim's dad mentions the webcam thing from the PTA meeting, he turns his head away from Jim. In the next shot, his head is suddenly facing Jim. (00:06:40)
Continuity mistake: Jim's mom drops the Tupperware of food with the top facing up, and when it lands, the top is facing down instantly. (00:03:30)
Chosen answer: Yes. That's the point of the theory. Men multiply the number of women they've had sex with by 3, women divide the number by 3.