There are two approaches to mathematics in this world, and both are elegantly laid bare by a bigamist, noisily en route to St Ives.
This wanderer, you will recall, was accompanied by seven wives, each of whom had seven sacks. Every sack contained seven cats, and every cat had seven kits. Given the general pandemonium that this caravan would have created as it passed by, caterwauling and kvetching, one could forgive roving census-takers for fudging their figures that day, particularly in the Cats and Kits columns; but in the quiet of the nursery or classroom there is less distraction; and so it is that young minds have been flinging themselves on to the riddle for centuries.
And it is precisely whether one clings or bounces off that determines in which mathematical camp one belongs.
Those who cling — thinkers to whom logic is an old friend — remain calm, and ask for more information. Did the narrator meet the bigamist going the other way, in which case only one man arrived in St Ives? The husband had had seven wives, to be sure, but was he still married to them all? Similarly, Cat X may have had seven kits at some stage, but was said X still accompanied by Kits X+1 through X+7, or had they scarpered as soon as the sacks came, heralding another cross-country hike?
Fully briefed, the arithmetically confident will soon reveal that the good folk of St Ives were later entertained by the sight of nine people dragging 49 sacks behind them, in which 2 744 kitties screamed vengeance from the most jagged pits of hell itself.
But matters are less clear for those of us long ago banished to the muddy straw of the arithmetical barn, who know our place as the village idiots of mathematics. Our handicap becomes evident the moment we begin to ask our own back-story questions. For instance, did he meet his wives in clubs, or were they friends of friends? Was he ever tempted to call them Sleepy, Grumpy, Bashful, and so on? And given that they were toting an awful lot of cats, and hadn’t brought anything else as hand luggage, were they in fact en route to the St Ives tennis racquet factory with another shipment of raw materials and, if they were, was the narrator going to tip off the RSPCA?
And away we go, plunging ever further away from reasonable numbers, our ineptness swelling the host of endangered kittens into the tens of thousands and making us anxious and depressed.
It is not a pleasant thing to be reduced to a glazed donut by the prospect of a few numbers arranged in a flirtatious riddle; but until recently we have been able to disguise our lack, and think of other things, like how many segments of Kreepy-Krauly pipe it would take to pump water from the Pacific to Mars, and so on. We could hide in company, suddenly remembering one last clever anecdote as the bill arrived and the addition started.
No longer. We have been outed, and shunted down into the half of the carriage for second-class adders. They look at our hand-me-down crossword puzzles or paperback thrillers, and smirk. And then they peel back another virgin page, covered in those bastard blocks, and smugly begin a fresh persecution of the arithmetically challenged.
Sudoku has some admirable uses. It is a superb contraceptive. It gives the English a reason not to speak to one another on trains, where before they had to rely on pointedly re-folded newspapers. But it has also cruelly singled out those of us who were taught addition and subtraction via detailed anecdotes about greedy gnomes and generous dew-fairies, in grade 11.
Which is why one can only hope that some enterprising maths imbecile soon patents Pseudoku. The 81-square grid will be identical; numbers 1 to 9 will be used as well: the adders will never know the subterfuge. But instead of divining and inserting numbers, the Pseudoku player finds them all neatly printed, and need only identify them, here circling a four, there crossing off a seven. Recognise and ring every number from 1 to 9, in any order, in any puzzle, to whatever end, and you win.
Easy as one, two, er—