Grade 4 studied the use of scale in art, first by viewing and discussing many works of interest in a slideshow: 

Giant Clothespin by Claes Oldenburg 

Their task was to draw an insect using observation skills from a photo, making it look as realistic as possible. Then draw the insect 2 more times so our eyes will pick up on the rhythm of a repeated image. The insect could go off the page partially for a more interesting composition. Finally, fill in some kind of background that reverses the scale of the insects, making them look large and the large elements of the picture appear small. The results were some very imaginative scenes, which they narrated to their classmates.