Tricky Sums and Psychology

In their first years of studying mathematics at school, children all over the world usually have to learn the times table, also known as the multiplication table, which shows what you get when you multiply numbers together. Children have traditionally learned their times table by going from '1 times 1 is 1' all the way up to '12 times 12 is 144'. Times tables have been around for a very long time now. The oldest known tables using base 10 numbers, the base that is now used everywhere in the world, are written on bamboo strips dating from 305 BC, found in China. However, in many European cultures the times table is named after the Ancient Greek mathematician and philosopher Pythagoras (570-495 BC). And so it is called the Table of Pythagoras in many languages, including French and Italian. In 1820, in his book The Philosophy of Arithmetic, the mathematician John Leslie recommended that young pupils memories the times table up to 25 x 25. Nowadays, however, educators generally believe it is important for children to memorise the table up to 9 x 9, 10 x 10 or 12 x12. The current aim in the UK is for school pupils to know all their times tables up to 12 x 12 by the age of nine. However, many people do not know them, even as adults. Recently, some politicians have been asked arithmetical questions of this kind. For example, in 1998, the schools minister Stephen Byers was asked the answer to 7 x 8. He got the answer wrong, saying 54 rather than 56, and everyone laughed at him. In 2014, a young boy asked the UK Chancellor George Osborne the exact same question. As he had…