Teachers use Scantrons so they would not have to hand-grade their students' tests.
Also, they are laid out such that test takers can cheat off others with very little effort.
The reason for this is because Scantrons are divided into sections of about 10 entries each. The entries have fill-in "bubbles" which are wide and generously spaced apart. Therefore, cheaters can get several answers by taking one slight glimpse of another person's Scantron -at any angle.
Tip: The best view is from the bottom. Another words, the Scantron of the person sitting in front of you(the answers show up very clear this way). When you get sight of it, count to yourself, 1,4,3,2,2,1,5,4,4,2,4,3,1, etc
student: HELL FUCKING YEAH!!