The book "How to become a lightning calculator" is written by an unknown author and is a unique guide that will help the reader to develop incredible computing abilities. On its pages you will find exercises that will help you quickly and accurately do complex calculations in your head. The book teaches the effective use of various calculation methods, which allows you to overcome the usual limitations of the duration of calculations. "How to become a lightning-fast calculator" will be an indispensable assistant for everyone who wants to improve their mathematical skills and increase their level of intellectual readiness.