Ten is an odd number ...

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Recently I read the translation of a tiny Bengali novel written by Sirshendu Mukhopadhyay for children. One of the characters is Karali Babu, a primary school teacher.

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‘It was rumoured that after eating his food, he did sums on the rice plate. He dreamt of complicated calculations. … would laugh and cry while going through a Mathematics book. At times, when he came across a wrong sum, he trembled in fear … Karali Babu not only taught them regular sums that were included in their course, but would import all kinds of scary mathematical problems from outside…The students did not call it Mathematics any more. It was so frightening that they had coined the term – Frightenmatics …’

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All the people I have talked to treat their Mathematics teachers differently than their other mentors, not necessarily for the same reason. Some are held in great awe and respect for handling an inscrutable subject; some are remembered gratefully for making a tough subject easy; and some for their impatience with laggards.

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I remember Prof Satagopan who taught us Projective Geometry in College for his meticulousness and commitment. He was passionate (No other word would describe his feeling) about Mathematics. The exact science ruled his life. Like the fictional Karali Babu, he dreamt math, ate math, drank math and lived math.

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The good Prof was as meticulous about everything in life as he was about math. He was so very predictable: the weekday could be determined by his attire. On Mondays, it was navy blue jacket and white trousers; Tuesdays, light grey jacket and black trousers, and so on. The shirt was always a spotless white and the necktie had small polka dots on blue or black background.

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He would come into the class exactly at the appointed hour, and go on till the bell rang to announce the end of a session. He did not believe in roll-call, and no peon dared enter his classroom with notices from the Principal, College Office, NCC, Canteen and the like. He seemed to believe that all those join the college attend the classes (and that those who do not are the losers).

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The moment the bell went, he would stop mid-sentence. Story, apocryphal of course, went that in the next class (which may be only the coming week or after the Christmas vacation) he’d start exactly where he had left off!

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Talking of Christmas, in the last lecture before the Christmas examination, he added, helpfully, ‘The problems for the exam will be similar to the discussed in the class. Of course, the numbers will be different…’ He paused awhile and added, with a straight face, ‘… But not all of them. Pi will still be 3.14159... ’

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The Prof had a very fine but subtle sense of humour. As with numbers, Prof Satagopan had a way with words. He’d say, ‘Two is the oddest prime of all, because it’s the only one that’s even!’

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A postulate of his was: ‘All positive integers are interesting.’ His proof, using reduction ad absurdum: Assume the contrary. Then there is a lowest non-interesting positive integer. But, hey, that’s pretty interesting! A contradiction. Hence proved.’

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In rare moments of playfulness, he’d throw a puzzle at us: ‘You are given 19 sugar cubes to be put into four cups of coffee such that each of them has an odd number of sugar cubes in it.’ We would struggle for hours and fail. When pressed for the answer, he’d say, ‘That’s easy: three each in three cups and ten in the fifth.’ We’d protest in unison, ‘But, Sir, ten isn’t odd!’. Without any hint of jest, he’d declare, ‘Ask your mother; she’ll confirm that ten is certainly an odd number of cubes to put in a cup of coffee ...’ With that, you’d never forget all your life that an even number of odd numbers can never add up to an odd number!

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His favourite joke was, predictably, a pun. One day, Jesus said to his disciples: ‘The Kingdom of Heaven is like 3x squared plus 8x minus 9.’ St. Thomas looked very confused and asked St. Peter: ‘What does the Teacher mean?’ St.Peter replied: ‘Don’t worry – it’s just another one of his parabolas.’