Career Day / Hey Harold! - S3-E11
Continuity mistake: There are more than 16 slips in the hat, but only 16 students in class, and only 12 hands went in to pull out slips.

Career Day / Hey Harold! - S3-E11
Continuity mistake: There are more than 16 slips in the hat, but only 16 students in class, and only 12 hands went in to pull out slips.

Girl Trouble / School Dance - S3-E18
Continuity mistake: Besides the fact that when Helga is sharpening her pencil, the desk arrangement changes, one of the students visible when she looks at Arnold is... Helga. This happens because the shot is taken from the episode "Helga's Love Potion."
Downtown as Fruits / Eugene's Bike - S1-E1
Trivia: Eugene's bike has a "YOOJ" (pronounced like "Eugene" without the "een") license plate.
Arnold's Hat/Stoop Kid - S1-E3
Question: Did Harold already know that the Stoop Kid had just left his stoop the first time? He would have known that a while ago due to a large crowd in the city or even in the newspaper.
Answer: No, he did not. He is seen getting off the bus with a suitcase, so he must have not been home for a few days so there is no way he could have known.
Bowling255 ★