Description Sangwigwon Yeonsan 960 approaches number and computation learning—the starting point of math and an essential tool across all areas—with a new philosophy and methodology. Through task-based computation problems combined with diverse situations, processes, and methods, this series not only completes students' computation skills but also builds 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 computation practice beyond the basics, children preparing for advanced curriculum applications, 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 steadily preparing from an early grade for gifted education programs, math 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 D1: 961–1020 Multiplication and Division D2: 1021–1080 Mixed Calculations D3: 1081–1140 Addition and Subtraction of Fractions D4: 1141–1200 Addition and Subtraction of Decimals [Recommended Grade] A must-have thinking-skills computation workbook for top-performing 4th grade elementary students Table of Contents D1: 961–1020 Multiplication and Division Issue 1: (3-digit number) × (2-digit number), (4-digit number) × (2-digit number) (1) Issue 2: (3-digit number) × (2-digit number), (4-digit number) × (2-digit number) (2) Issue 3: (2-digit number) ÷ (2-digit number) Issue 4: (3-digit number) ÷ (2-digit number) Answer Key Included