In this high-tech era teachers often look askance at blackboards, most of which aren’t even black any more. Blackboards are something math instructors still scribble on, and are good for leaning against, although they dust your clothing and make you sneeze. And we all cringe when badly angled chalk buzzes our teeth and jars our ears. This sometimes snobbish, always unfortunate attitude closes off many teachers from what can be a most effective and flexible aid to teaching through discussion methods.
