![Napoleon Dynamite mistake picture](/images/screenshots/67000-67999/67636_sm.jpg)
Continuity mistake: When Napoleon is waiting while Rico makes a sale, he checks his watch to see how much time he has before the dance. The first time he checks it, the date on the watch indicates Thursday July 17. When he checks it again a few minutes later, it shows Monday July 21.
Answer: Because it is such a small town that the school system can not afford buses for grade level so they have to share them, plus it has comedic value as well.
pross79
Small town schools are usually K-12. The other older "cooler" students drive to school or get ride with their friends.