Description: Sangwigwon Yeonsan 960 approaches number and operations learning—the starting point of math and an essential tool across all areas—with a new philosophy and methodology. Through task-solving-type number and operation problems combined with diverse situations, processes, and methods, this workbook not only completes computational skills but also cultivates higher-level mathematical thinking. Sangwigwon Yeonsan 960 will be a great support for children who get bored or tired of simple repetitive computation drills, children who need creative-thinking-based computation learning beyond basic operations, children who want to deepen and apply their curriculum computation skills, children who need to think through math rather than solve problems mechanically, children who want to build a solid foundation rather than rush into excessive advanced learning, children preparing step by step from an early grade for gifted education programs, olympiads, or specialized middle/high schools, and indeed any child who loves math and wants to excel at it. [Book Composition] 6 books for Level P, 4 books each for Levels A–D, 22 books total - C1 (721–780): Addition and subtraction of three- and four-digit numbers - C2 (781–840): Multiplication - C3 (841–900): Division - C4 (901–960): Fractions and decimals [Recommended Grade] Essential critical-thinking computation workbook for advanced 3rd grade elementary students Table of Contents C4 901–960: Fractions and Decimals Issue 1: Principles of Fractions Issue 2: Understanding Fractions Issue 3: Comparing the Size of Fractions Issue 4: Understanding Decimals Answer Key