Experienced editors from the British national organization MENSA offer you 156 different tasks, one way or another related to Arabic and Roman numbers and numbers. To solve them, you may have to "mobilize" not only mathematical abilities, but also knowledge in the field of physics, astronomy, other exact sciences (within the school course), as well as - and this is perhaps the main thing - ingenuity, observation, the ability to think logically, spatial imagination. The dictionary and tables that are in the book will help you understand the initial conditions of the tasks correctly.