Decimalisation: a look forward to 1971
Article reproduced from the Savings Banks Institute Journal, March 1969
Long, long ago, when I was a lad, there was a useful coin called a farthing which could buy all manner of things - a thick bar of chocolate, a reasonable poke of sweets, a cigarette (if you knew the right shop in the right back-streets to patronise) and if your change from shopping at the baker's contained a farthing, you could elect either to take the coin or a 'farthing biscuit', which was a large sugar-encrusted slab which kept you munching happily all the way home, and if you had a hard job explaining why your change was d short - well, you couldn't have your biscuit and eat it too. The halfpenny was quite valuable and if you had a silver threepenny, then you were really in the moneyed class. As for having a half-crown - gosh, it was an awesome thing, representing enormous wealth, which you gripped with both hands and sighed with relief when you finally turned it over to safer hands than yours.
Some of you may never even have seen a farthing; a silver threepenny may be an oddity to you; a halfpenny may be an insignificant bit of bronze and even a half-crown may be just the equivalent of ten inferior cigarettes, to be blown away in smoke. All their former glory has been blown away and soon the threepenny, the halfpenny and the half-crown will join the farthing in the limbo of forgotten things - the halfpenny on the first of August this year and the half-crown on the first of January next year. In time, also, the penny, both kinds of threepennies and the sixpence will disappear. The present shilling and florin will no doubt soldier on for a long time but they also will some day fade away. Their life will be prolonged only because they are the equivalent of the bright new cupro-nickel 5p and 10p pieces which are already in circulation and which are the first decimal coins which we have in use, but do we think of them as the decimal part of a pound or just as the new kind of shilling and florin - 05 or 10 of a pound, or just one-twentieth or one-tenth of a pound?
Herein will lie the difficulty for older people, buy you younger people will probably soon forget old equivalents and simply look on the new coins as incomparable prime coins, if one may use such a phrase. The new bronze coins will be the p (the size of the old silver threepenny-piece), the 1p (similar in size to the old farthing) and the 2p (about the size of a halfpenny).
The new cupro-nickel coins will be the 5p and the 10p (interchangeable with the 1/- and the 2/- pieces); and the 50p (which is alarmingly described as 'an equilateral curve heptagon slightly smaller than a half-crown') will take the place of the ten-bob note. It will be in our pockets as early as October this year - in quantity, many will hope.
One of the big problems for you who are cashiers (if we are to accept the experience of the Australians in their changeover) will be the handling of small coins - the p and 1p in particular - to which you are not accustomed, and it is recommended that as soon as supplies or similarly-sized 'dummies' become available, you should spend time actually handling these new coins, mixed up with those items of the present coinage which will still be current during the changeover period, so that you can gain not only slickness in handling all the different sizes of coins, but experience in the relative values of them. Upon your efficiency in handling the new coins will depend the reputation of your bank in this particular field of countercraft.
Another problem which will face you will be the conversion or exchange of new coins for old. You will, in due time, be provided with conversion tables, the application of which, by and large, will result in negligible differences in exchange values. But tables cannot provide for all the combinations of coins which will be presented to you, and you may and most likely will have to exercise judgement in deciding what equivalent values to give. No doubt your Manager will guide you in this, but keep in mind that if the difference, tiny though it may be, is always in favour of the bank, its reputation will inevitably and quickly suffer. It may be fairly cheaply-bought goodwill if small differences are always in favour of the depositor, but this must be decided by individual banks. The Chairman of the Decimal Currency Board in Australia has said that a point which impressed him forcibly was how some firms which had spent fifty years building up goodwill lost it practically overnight by adjusting prices so that they were always in favour of the firm. Actually, this is going to be a very difficult problem in management policy, because the seemingly insignificant difference in exchange value could play havoc with the profit margin in fast-moving, small-unit items like confectionery, packed foods, etc., and wise traders will begin now to adjust prices slowly and imperceptibly so that in due time conversion to decimal currency can be made to the almost exact equivalent of present money.
It is not too soon to be 'thinking in decimals'. For years and years I have been doing money calculations in decimals and the mental conversion of shillings and pence to decimals of a pound is second nature to me. Some of you may need to have a look at your old arithmetic books again and the sooner you start practicing the better. The conversion of shillings is easy; I once had it described to me as 'Multiply by 10, divide by 2, stick the damned dot in front and Bob's your uncle!' Thus 17/- x 10 = 170 2 = 85, put in the dot and you have 17/- as 85 of a pound. The pence are a little more difficult, but the rule is 'Multiply pence by 4, and if the answer is more than 12 add 1, if more than 36 add 2; then add noughts after the decimal point to make up three digits'. Thus 1d = 004; 7d = 7 x 4 = 28 (being more than 12), add 1 = 29; add a nought after the decimal point to make up three digits = 029; 10d = 042 (10 x 4 + 2). It takes very little practice to become speedy at these conversions, which give close approximations, to three decimal places, to parts of a pound. However, as the new currency will be to two decimals with the peculiarity of a vulgar fraction p being stuck on the end of the decimals occasionally, these rules (as far as pence are concerned) are going to be of little value, but still you should practice mental calculations.
Some may say, however, that there is little point in wasting mental powers in doing these calculations when there are conversion tables and machines there to do the job for you. A good answer to this could be given Garnett-wise, with an extension of language even he doesn't use in public, relating to philosophical outlook and moral and mental attitudes. In spite of this good answer, there will in due course be produced a variety of conversion tables, mechanical aids and the like. There are a number of these already on the market, but beware, none has so far received the blessing of the Decimal Currency Board - indeed the official rates of conversion have not yet been issued, although it is expected that the official table will provide for rounding up by 2d in converting 1d and 7d, 4d for 2d and 8d, 6d for 9d; and rounding down by 2d for 5d and 11d, 4d for 4d and 10d and 6d for 3d.
'Thinking in decimal values' is going to be a bit of a trial. Shillings and pence are so familiar to us that we shall be inclined, for some time after decimalisation, to re-convert the decimals in our own minds, and the fact that we shall still be seeing the old-fashioned shilling and florin coins will almost automatically make us think of these coins as they are now, instead of Fivepennies and Tenpennies. No longer should we be thinking of 1. 17. 6. as 37/6d but as 1.87 - or are we likely to think of it as 187 new pence? Let us hope that we do not make confusion worse confounded. The sooner we really start 'thinking decimal' the better.
I have mentioned the peculiarity of the vulgar p being added to decimals. Banks, not being vulgar, will not use p in their records of sums of principal. It may be said there is nothing new in this - we don't record the present d. True, but the new p, being worth 12d, is of sizeable value, and we shall have to use it at least - if not a few more places of decimals - in our interest calculations, if they are going to be anywhere near exact. This problem of interest calculation is proving rather intractable, but it is having the close attention of committees of the Association, the Post Office, Treasury and Bank of England. When it is solved, your task is simple - you have to apply the rules laid down!
This short talk has been superficial and simple, yet fundamental. D-Day is 15th February, 1971 - about two years to go. Plenty of time to start 'thinking decimal'? Plenty of time to start practicing the handling and evaluating of the new coins? Plenty of time to start practicing converting shillings and pence to decimals? It's later than you think!

(MACA talks to students: SBI Journal, March 1969, page 46)