65 x 39 = 2535 108 x 312 = 33696 27 x 84 = 2268 Can you work out these calculations in your head? Many of us would say "No way " For anyone who reads this book and learns the tricks it contains, it won't be difficult anymore. This book aims to stimulate enthusiasm for math through rapid calculation, thereby creating a solid mathematical foundation for further learning. The goal is to express profound...