ABSTRACT
All throughout the following week, holding paper, pencil and a calculator, Louis was determined to find a similar ‘trick’ for the other tables. From time to time he would come up to me, very excited, saying that he had found the trick, but when he started to explain it to me he began to realise that it did not work. I observed him adding, subtracting, making up new rules, checking the results in order to get his trick right. By the end of the week his enthusiasm had begun to fail.
