The central concerns of mathematics are not numbers, but patterns, structures, symmetries and connections. Take, for example, the Sudoku puzzles that appear daily in newspapers. The objective is to complete a 9 x 9 grid, starting from a few given numbers or clues, while ensuring that each row, each column and each 3 x 3 block contains all the digits from 1 to 9 once and only once. But the numerical values of the digits are irrelevant; what is important is that there are nine distinct symbols. They could be nine letters or nine shapes. It's the pattern that matters. One Irish daily paper publishes these puzzles with the statement 'There's no maths involved, simply use reasoning and logic!' It seems that even the idea that something might be spoiled by mathematics is enough to scare off potential solvers! Could you imagine the promotion of an exhibition in the National Gallery with the slogan 'No art involved, just painting and sculpture'? If you can do Sudoku, you can do maths!