The author spent many years teaching at a selective school with the constant challenge of including the most able students, whilst at the same time avoiding the danger of excluding the rest of a class. These blackline masters are the result: many of them include fairly routine work, but each graduates to more difficult questions to provide a challenge for the really able. The answer sections provide guidance on these difficult questions. Book S&X topics covered include: Early probability and data handling; Probability taken further; Looking at data; Possibilities and probabilities; Modulus arithmetic; Triangular numbers; Half pint mugs; Areas and lattice points; Production and Marketing; Matrices; Strange rollers; Drilled and painted cubes.