65 x 39 = 2535108 x 312 = 3369627 x 84 = 2268Can 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 mathematical ideas in simple language, conveying the magic and mystery of calculation. As long as you can multiply two-digit numbers, do addition and subtraction, and understand simple negative numbers, you can handle the basics of this book.