The conversion to automated switchboards, by now taken for granted, has revolutionized telephone use. Department stores and schools hold instruction sessions for as many as 600 to 1,000 people at once. Some ask simple-sounding questions like "Is it true that you can omit dialing the zeros?" Many look closely at the unit calling system that automatically adds charges for each call, worrying that they will lose considerable amounts of money on wrong-number calls that they could previously ask the local operator to overlook. There is a good deal of confusion as the new users are added.