From Darren:
who points out, “I don’t think I’ve ever referred to connect-the-dots type exercises (puzzles?) as “paint-by-numbers”. Is that what’s happening here? It doesn’t look like they’re creating a paint-by-numbers image for later fill in, and there’s certainly no painting being done.”
Indeed.
Comics I Don't Understand 
No idea what’s going on, but I liked the “Airplane!” reference.
It’s an introductory class. The first step is understanding what order the numbers go in.
The joke is that it is obvious where this is going and despite how obvious it is the professor doesn’t want a student jumping ahead.
It would make a bit more sense to call this introductory connect the dots, but the joke is still the same.
The bigger question is how the professor knows he is jumping ahead.
I think the professor has had past experience with Michael getting ahead of everyone.
They’re painting in the black lines between the numbers. It’s introductory in that instead of a 2-dimensional picture with multiple colors, it’s 1-dimensional and a single color.
What were steps 1, 2 and 3? There are only 2 lines. Steps 2 and 3 seem obvious. Was step 1 putting in the dots and numbers?
What’s the Airplane! reference?
Oh, the title. Didn’t spot that, just read the comic.
Actually, I don’t see what the title has to do with the comic.
Just a cheap “counting” reference!
I always hated that “don’t get ahead of everybody else.” The only time it is appropriate to NOT get ahead of everybody else is when you are playing in an orchestra.
Like when one is in still in school and everyone is reading the same book and one has finished the entire book while everyone else is still on the second chapter?
Then again, sometimes one learns that one does not actually need to read the book at all to be able to answer the teacher’s questions. (This drove Robert crazy when we took English classes together in college. )