155 words on Uni
I've noticed this many times by now in our large lecture theatres where there are sets of three blackboards behind each other: People, even old and experienced lecturers frequently fail to make good use of them. Either by not making sure you can always see the blackboard they wrote on just before, by simply ignoring the backmost board etc. So handling them properly does seem non-trivial. And looking at the different combinations the blackboards can be in assuming that the lecture hall is only high enough for two of them to be visible at once, it seems that using all three of the blackboards at the same rate isn't possible if you want to achieve the maximum viewing comfort. Unless I'm mistaken, you'll have to use the backmost board first, then the front one, then the middle one, the front one again and restart with the backmost one. So the frontmost board gets used most.