Description Sangwigwon Yeonsan 960 approaches number and calculation learning—the starting point of math and an essential tool across all areas of the subject—with a new philosophy and methodology. Through task-solving style number and calculation problems combined with diverse situations, processes, and approaches, this workbook not only completes your child's calculation 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 calculation drills, children who need creative-thinking calculation practice beyond the basics, children looking to deepen and apply their school curriculum, 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, math olympiads, or specialized middle/high schools, and any child who loves math and wants to excel at it. [Workbook Composition] P-level: 6 books, A~D levels: 4 books each — 22 books in total B1 (No. 481–540): Addition and subtraction of two-digit and one-digit numbers B2 (No. 541–600): Addition and subtraction of three-digit/two-digit numbers B3 (No. 601–660): Addition and subtraction of three-digit numbers B4 (No. 661–720): Multiplication tables [Recommended Grade] An essential critical-thinking calculation workbook for top-performing elementary 2nd grade students Table of Contents B2 (No. 541–600): Addition and Subtraction of Three-Digit/Two-Digit Numbers Issue 1: Three-Digit Numbers (1) Issue 2: Three-Digit Numbers (2) Issue 3: Addition and Subtraction of Two-Digit Numbers (1) Issue 4: Addition and Subtraction of Two-Digit Numbers (2) Answer Key