A representative mother's workbook, 『Kitan Math K Level 1: Addition and Subtraction of Rational Numbers』.
In Level K, the goal is to improve calculation skills for rational numbers by practicing addition, subtraction, multiplication, and division of rational numbers based on the calculation skills for natural numbers, fractions, decimals, and mixed arithmetic developed in Level J.

* Features of this book
① Program-based learning materials that solidify computational skills, the foundation of mathematics.
② Customized learning tailored to each individual's level, from infants to middle school students
③ High learning achievement through clear learning objectives
④ Thorough supplementary learning through achievement tests and end-of-course tests (levels C to K)
⑤ Special Appendix 4-minute sentence problem study (levels C to K) to develop calculation and thinking skills at the same time!