It's more common than you would think. I've lost track of how many people of all ages come in to my area that can't read a scale or any other measuring device. Had to fail one 40 something guy due to the fact he had no clue as to what the difference was between the 1/32, 1/64,.10 and .01 scales on a standard 6" scale. Well over 90% of the people I deal with can't even do math well enough to convert an ohm of resistance into 1000 milliohms without a conversion aid card. I guess that's why so many things are made outside the US rather than inside now days