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-solving computation problems that combine various 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 help for children who get bored or tired of simple repetitive computation practice, children who need creative thinking-based computation learning beyond basic arithmetic, children who want to study advanced applications of the curriculum, children who need to think through math rather than mechanically solve problems, 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 all children who love math and want to excel at it. [Book Composition] 6 books for Level P, 4 books each for Levels A–D, 22 books in total - B1: 481–540, Addition and subtraction of two-digit and one-digit numbers - B2: 541–600, Addition and subtraction of three-digit/two-digit numbers - B3: 601–660, Addition and subtraction of three-digit numbers - B4: 661–720, Multiplication tables [Recommended Grade] Essential thinking-skills computation workbook for top-performing 2nd grade elementary students Table of Contents B3 601–660: Addition and Subtraction of Three-Digit Numbers - Issue 1: Addition and subtraction of three-digit numbers without carrying/borrowing (1) - Issue 2: Addition and subtraction of three-digit numbers without carrying/borrowing (2) - Issue 3: Addition and subtraction of three-digit numbers with carrying/borrowing (1) - Issue 4: Addition and subtraction of three-digit numbers with carrying/borrowing (2) Answer Key Included