Chapter 6, The First Hebrew Algebra, part 2

Of course, we have to be careful not to mix two numerations. If we are working a sum in tens, we must go on working in tens to the end of that sum. Never let yourself get fixed ideas that numbers (or anything else that you are working at) will not come right unless your sum is set or shaped in a particular way. Have a way in which you usually do a particular kind of sum, but do not let it haunt you. must learn it.” But do not take in vain the names of great unseen powers to back up either your own limitations, or your own authority, or the Inspector's authority. Never say, or imply, “Arithmetic requires you to do this; your sum will come wrong if you do it differently.” Remember that arithmetic requires nothing from you except absolute honesty and patient work. You get no blessing from the Unseen Powers of Number by slipshod statements used to make your own path easy. Be very accurate and plodding during your hours of work, but take care not to go on too long at a time doing mere drudgery. At certain times give yourself a full stretch of body and mind by going to the boundless fairyland of your subject. Think how the great mathematicians can weigh the earth and measure the stars, and reveal the laws of the universe; and tell yourself that it is all one science, and that you are one of the servants of it, quite as much as ever Pythagoras or Newton were.