Character mistake: The math test Tina gets a D on has #5 marked wrong. However it is correct. (Additionally it seems improbable she would actually get #3 and #4 wrong since she obviously understood the concept of how to do the problem and only had a problem with the division for some reason, and these questions didn't require division).
Continuity mistake: When Jimmy Jr. Comes up to Tina, Gene's lunch tray has no hot dog or milk, but when it cuts to the other angle, there's now a hot dog and milk.
Answer: It's a made up song for the show. It's a synth version of what the kids sang in Mr. Frond's video at the beginning of the episode. "Let's Swap Eyes."
Bishop73