Scantron

Back in middle school, we used Scantron cards for taking multiple choice tests.
You had to use a number two pencil to mark the boxes.
The teacher would collect up the cards, run the answer key through the machine, and then run each card.
The more answers the student got wrong, the louder the machine got, stamping the errors.
Being a smart kid, my card went through quietly.
But the dumb kids’ cards provoked angry rattles from the machine.
One kid was so dumb, the machine started to smoke, and it shook itself off of the table.
And caught fire.