Revealing: The announcer says the bikeathon begins "at the gun", but then somebody sounds an air horn to start the race.

Factual error: Arnold's phone number is "555-123", but all phone numbers in the USA have seven digits.

Continuity: In "Longest Monday" at one point in the episode, Arnold and Gerald run off of a bus and down an alley. Two fifth graders come chasing after them. In the next scene, you see Arnold and Gerald hiding in the sewer under the 5th graders. Arnold then crawls through a very narrow tube, and Gerald follows. You then see the end of the tube and Gerald come out of the it first, and Arnold climbs out last. It would be impossible for Arnold and Gerald to switch places inside the tube because it was way too narrow.

Continuity: In "Miss Perfect", Helga, Rhonda, Sheena, Phoebe, and Nadine are cooking up ways to make Lila's (the new girl) life miserable. In one shot, Rhonda is wearing her new blue outfit. When the scene cuts to the boys and Lila, and then back to the five girls, Rhonda is wearing her standard red sweater and black pants. For the rest of that day, she is back in her new outfit.

Continuity: When Lila is finishing her first joke, Rhonda suddenly switches from her French outfit to her "usual" one; also, during the Jell-O incident, her beret disappears and then reappears.

Continuity: The clock in the police station looks like it says it's after 5:00, but school is in session.

Revealing: Arnold and Gerald's lockers don't have padlocks, like most of the others do.

Continuity: The next night, Phoebe's bed clothes switch back and forth between her nightgown and her dress.

Continuity: Chinese Checkers is supposed to be with ten pieces per side, not six.

Continuity: The digits on Arnold's clock get bigger and change shape while he's talking to Grandpa.

Continuity: In the last scene, Rhonda is seen through the bus's rear window as sitting in the back of the bus - but just before that, she's talking to the girl with the frizzy hair in a seat closer to the front.