LIGHTNING ARITHMETIC

New Zealand Herald, Volume LXIX, Issue 21213, 20 June 1932, Page 11

LIGHTNING ARITHMETIC

AUCKLAND MAN'S GIFT. CALCULATING FOR PLEASURE. NUMBERS IN EVERYTHING. Lightning mental calculations that make the non-mathematical mind reel are the hobby of Mr. P. Corbett, traveller for'an Auckland business house, who Knows how many spots there are on a yard of wallpaper and the number of paces between Onehunga and Auckland. Should he be asked the amount of interest due on £1296 at 3£ per cent, he will answer within three or four seconds that it is £45 7s 2d, and with equal facility will reply that 28 cubed is 21.952. "I have had no training," said Mr. Corbett on Saturday. "It is a gift that was born with me. lake an easy example—the progressive multiplication of the figure seven—and write the answers down : —Seven sevens are 49, seven times that is 343, seven times 343 is 2401 . . At an ever-increasing rate lie continued the process to seven times 282,475,249, giving the correct result of 1,977,326,743 before pausing for breath. Checking Proves Accuracy. Submitting to a mild mental test he cubed each numerical quantity from 11 to 30 as quickly as the answers could be written. Subsequent checking proved the:r accuracy, lie then added several nine-figure rows, writing the answer after only a second's pause to scan the problem, and commencing on the left hand of the column first. There was not a moment of hesitation between the first figure and tile last.

"In the ordinary routine of my business I ha\e no occasion to use figures," sa:d Mr. Corbett, "but rapid calculation such as this should be useful in costing or stocktaking. For instance, 1967 yards of cloth at 7d a yard aro worth £57 7s sd. I was told by one Dusiness man that 1 would be as quick as 10 men at stocktaking. I can beat a calculating machine, especially on multiplication. ."'People have asked me if I do not memorise. I can assure you that I do not. although in working out percentages I have a system of my own. Ordinary calculations I do by the long method, which everybody learns The only difference is that I do them quickly. The very appearance of a number tells me what numbers will divide into it and what will not. A curious thing is that in my very early days at school I was taken out of one class and put into a lower class because I could not do my sums. Abilities as a Eoy. "I went to the To Aro School, Wellington, and from the age of 11 years onwards did all my school arithmetic mentally. 1 was able to do 20 sums while the other children were doing five. For four years running I won the Chamber of Commerce prize and won a junior free place and a Queen's Scholarship with 100 per cent, in arithmetic in each case. When I was 11 years old I gave a demonstration in calculating to the Wellington Chamber of Commerce. "Figures are in my mind all the time and I find myself calculating subconsciously. 1 count the spots on the wallpaper, the people in the trams and even the bars on the birdcage. Take the beads on that lampshade. Tn half a scallop there are 16 strings and about 60 beads on a string. That is 1920 beads to a scallop, and 11 scallops gives 21.120 beads on the shade. While I am talking to you ] am counting the buttons on your coat and the spots on your tie. If I go to the pictures I coiint the number of people and calculate the takings at the box office. Mind the steps when you go out. There are 37..". There were.