"Eighty dollars," I replied, as soon as he had the question out of his mouth, for my father had practised me thoroughly in all the short methods of computing interest.
He gave me half a dozen other problems; but, as he selected only those which he could solve in his own mind, I was very prompt in my replies. He then wrote out an example in averaging accounts, and as it was not a difficult one, and involved only round numbers, I did it very readily.
"But the most important thing with us," added Mr. Whippleton, "is simple addition. I don't like to wait half an hour for a clerk to run up a column of figures."
He then wrote about twenty sums of money, each having five or six figures, and told me to add them. My father had always assured me that simple addition tried the young accountant more than anything else, and he had insisted that I should practise it until I could run up a column as rapidly as my eye could take in the figures. I had used this exercise for months, until I flattered myself I could give the sum of a column as quick as any practised book-keeper. At the same time, he had taught me his own method, that of taking two figures at once, and adding their sum to the result already obtained. It was just as easy for one quick at figures to add thirteen, sixteen, eighteen, or nineteen, as it was to add three, six, eight, or nine. Thus, if the figures in the column were 6, 5, 4, 7, 9, 3, 8, 2, 9, 1, my father added them in couples, for it required no effort of the mind to add six and five, four and seven, nine and three, eight and two, or nine and one; and the mental process was eleven, twenty-two, thirty-four, forty-four, fifty-four.
I had practised this system until I could carry it along as rapidly as I could by adding a single figure at a time. Mr. Whippleton made his figures in duplicate when he wrote them, and added one himself to prove that I was right or wrong. Before he was half done, I had my result.
"You are wrong," said he, decidedly, when he had finished. "I would rather have you use twice as much time, and have the result right, than do it quick, and have it wrong. Accuracy first, and speed next."
That was just what my father had always told me, and I was rather mortified at the failure. I went over the columns again, with the same result.
"I get it so again, sir," I replied, when I had added the columns in an opposite direction from that taken the first time.
Mr. Whippleton added his figures a second time; but there was still two hundred dollars' difference in the two amounts.
"You add mine and I will add yours," said he, as we exchanged papers.