Check out this collection of posters made for classrooms in the 1970s. The captions have been removed, and newer (and funnier) captions attached by Michael Roberts of Denver Westword. The caption for the above image is "I'll bet I can make big bucks selling those chemicals on the side."
This image has the new caption, "I'd do a helluva lot better in this job than he would -- and be paid 60 percent of his salary."
Link -via Boing Boing