This is a problem book based on "Easy-to-Understand High School Mathematics I+A." It's a write-in style with very easy-to-write-on paper. From basics - suitable for those who are not good at math. You can use this problem book even without a textbook. There were pages with some problems solved in Chapters 3 and 4. The writing was in pencil, so I erased it with an eraser, but some traces remain. For those who don't mind. Will be shipped via Yu-Packet Post. Retail price: 1210 yen #MathProblemBook #Basic #HighSchoolMath #MathI