If a scholar is not prepared, it is not of much consequence whether it is because he forgot his book or mistook the lesson; or if it is ascertained that his answer is incorrect, it is ordinarily a mere waste of time to search for the particular error.
"I have looked over my work, sir," says the boy, perhaps, "and I can not find where it is wrong." He means by it that he does not believe that it is wrong.
"It is no matter if you can not," would be the proper reply, "since it certainly is wrong; you have made a mistake in adding somewhere, but it is not worth while for me to spend two or three minutes apiece with all of you to ascertain where.

Try to be careful next time." Indeed the teacher should understand and remember what many teachers are very prone to forget, namely, that the mere fact of finding an arithmetical error in a pupil's work on the slate, and pointing it out to him, has very little effect in correcting the false habit in his mind from which it arose.
The cases of those who are unprepared at a recitation ought by no means to be passed by unnoticed, although it would be unwise to spend much time in examining each in detail.
"It is not of much consequence," the teacher might say, "whether you have good excuses or bad, so long as you are not prepared.

In future life you will certainly be unsuccessful if you fail, no matter for what reason, to discharge the duties which devolve upon you.

A carpenter, for instance, would certainly lose his custom if he should not perform his work faithfully and in season.

Excuses, no matter how reasonable, will do him little good.