The blackboard in the classroom is a mess of black smudge often. It has been conjectured that the cleaning staff is using the wrong chemicals on the board, or perhaps not using them often enough. Once the eraser gets ruined with black gunk, reusing it makes the board worse.
Below some students and I clean up to the board with water spray and paper towels. Of course we had to get a new eraser or else the board would get ruined again. Photos are courtesy of Matt Lamoureux.
Return to course page here.