He ought occasionally to say to such a one, "I perceive you do not answer," and ask him questions individually.
4.

In some cases there is danger of confusion in the answers, from the fact that the question may be of such a nature that the answer is long, and may by different individuals be differently expressed.

This evil must be guarded against by so shaping the question as to admit of a reply in a single word.

In reading large numbers, for example, each figure may be called for by itself, or they may be given one after another, the pupils keeping exact time.

When it is desirable to ask a question to which the answer is necessarily long it may be addressed to an individual, or the whole class may write their replies, which may then be read in succession.
In a great many cases where simultaneous answering is practiced, after a short time the evils above specified are allowed to grow, until at last some half a dozen bright members of a class answer for all, the rest dragging after them, echoing their replies, or ceasing to take any interest in an exercise which brings no personal and individual responsibility upon them.