APPLIED ARITHMETIC

New Zealand Listener, Volume 14, Issue 353, 29 March 1946, Page 14

APPLIED ARITHMETIC

(Written for "The Listener" by

B.

Heymann

PPLIED Arithmetic is a branch of mathematics with which I have been familiar all my life. At school it served to demonstrate certain economical morals or moral economics: Dick Whittington collected pins, and the money he got for them he bought a cat, with the cat he caught mice, and before he knew where he was he was Lord Mayor of London. Moral: Look after your pennies (or pins), and your pounds will look after themselves, At home we got it in a more practical fashion. If we did not buy that worthless midday paper (said my father) in which we read only what we had read in the morning or would read in the evening; if we did not buy it but saved the penny every day, we would in so and so many weeks or months or years, be able to buy-lI forget what, but presumably a motor-car. In the course of time one begins to find out that most morals have their counter-morals, frequently also phrased as proverbs or neat little sayings. Wise men, the inventors of proverbs and neat little sayings, take this precaution in order to meet every eventuality. The main thing is that they should remain wise, so if somebody who has looked after his pennies and finds that the pounds failed to look after themselves should complain, they can always answer that "penny wise is pound foolish," and their reputation is saved. The look-after-your-penny attitude was that’ of the Pre-World-War-One generation, of the men who preferred Having Their Cake to Eating It, who thought and talked of a Rainy Day. ~ * * HAD almost forgotten the whole method of Applied Arithmetic during those years until I met it again-on my honeymoon. In the Swiss Hotel at which we were staying, afternoon tea was not "included", and we were given the choice between "thé simple,’ meaning just tea and bread and butter at 1 fr. or "thé complet" at 2:50 frs. which comprised tea and toast and a whole waggon-load of the loveliest cakes and pastries to choose from. While we were having our first afternoon tea (complet) my newlyacquired and dearly-beloved husband worked out that having simple instead of complete afternoon tea for three weeks would mean that we could stay two more days than we intended. I felt very much at home when I received this information, because my father on a similar occasion had told us that the money we spent on afternoon teas could provide a week’s holiday for a family of four, train fares included. I can’t say that I think much of the method. There was no point in saving up for the complete works of Shakespeare since we had got them already, and by the time our tram fares (even if invested on compound interest) could have mounted up to buy us a motor car, everybody probably would be wanting autogiros and we would have had to start all over again. Taking "thé simple" would not have served to prolong our stay by two whole days since we could not have stayed longer than originally planned, and going without afternoon tea altogether would have made sense only if we had given the money thus

saved to some family of four to spend on a week’s holiday (train fares in_cluded). But this was never done, and all the darned method does for me, for one, is to make me feel choked while I am swallowing cream puffs apa chocolate éclairs. It is a little better, though, ice the method of Applied Arithmetic is worked the other way round. In this case it is called "redemption" and serves to justify a purchase. When the Old Man wanted to buy a motor mower, he did not just go and buy it. He first made his calculations, employing Applied Arithmetic. "The lawn is too big," he said to himself (and later to me), "I shall have to pay somebody to tut it for me. This will cost me .10/- a week, i. £20 a year, allowing for thé winter months which need less cutting (one must never cheat oneself). A motor mower costs £35, therefore it will be "redeemed" in two years (allowing £5 for petrol and small repairs). Therefore, in two years’ time the motor mower costs nothing and from then on less than nothing." Having arrived at this conclusion his conscience was at rest, and he went and bought the motor mower. I enjoy using the method in his own favour, and I have become accustomed and rather insensitive to its being used against me. I do not employ it myself. I find it a strenuous way of making a decision. For me, if I want to buy something, there exists only the question whether I have got the money to do so. But I seldom have. * % Ea Not always does Applied Arithmetic appear in the shape of moral economics.. Sometimes it takes the form of detached meditations, related to statistics and furnishing most amazing revelations which are bound to raise one’s ‘self-esteem or one’s opinion of others where one would scarcely have expected it. In memory of its most famous instance we call it "Chess-Board Philosophy." Everybody has applied arithmetic in this fashion at some time ‘or other. There was an article in The Listener once informing us of the numbers of Bakers, Butchers, and so forth who could be found in the Wellington Directory-demonstrating to the Bakers,

no doubt, that they were-a-considerable community of their own. There was ‘another one, also in The Listener, which ‘told us how many fine, half-fine and utterly raimy week-ends we Wellingtonians had had during the past year, making us all feel justified in our frequent week-end complaints about the weather, We have worked out a few equally interesting calculations among ourselves. Thus:It takes a man ten minutes every morning to shave. Assuming that he started at the age of 20 (a very conservative estimate) and that he lives to be 70, that means that he devotes ten-times-seven-times-fifty-two-times fifty minutes of his life to shaving; in other words 182,000 minutes, which equals approx. 130 times 24 hours or, the working day being a day of eight hours, 390 working days. Allowing for Sundays and holidays this would mean that a man who lives to be 70 spends the working hours of about one and a

half years in shaving. In other words: if a man reaching the age of 20 decides to get his whole life’s shaving done then and there, he would have to start on the first of January of one year, stand in his bathroom from Monday to Friday, from nine in the morning to half-past-five in the afternoon (with half an hour’s lunch time) and shave, Shave, SHAVE until the thirtieth of June of the following year. Or: of two men living to be 70 the one who grows a beard has actually one and a half years more to enjoy himself in than one who shaves. I am sure that all men would grow beards were Applied Arithmetic a more generally practised science. A man living in Waterloo and going to work in Wellington for 20 years (again a very conservative assumption) travels twenty miles every day. Working five days a week and forty-eight weeks a year he covers 96,000 miles in those twenty years. He actually travels more than twice round the equator. I cannot see why they make such a fuss about world cruising. The gentleman who attends to the lift in a well-known Wellington building told me the other day that he makes between 200 and 300 trips a day. I think I am not far off in assuming that doing all his "ups" in one go he would reach the summit of Mount Everest in less than, three days and in doing his "downs" in the same way he would be back home before the week is out. In the Empire State Building the task might be accomplished in an even shorter time.