Stored at home, mostly unread. This is the best-selling reference book "Katarikakeru Chugaku Suugaku" (Talking Middle School Math) by Kazuo Takahashi. It's a highly-regarded book for those who struggle with math or want to relearn it as adults. Explanatory format: The book progresses in a lecture style, as if the author is speaking to you, making it easy to understand even when studying independently. Overwhelming volume: Although it's over 700-800 pages thick, it carefully explains the basics, starting from the very foundation of "why things are the way they are." Presentation of incorrect answers: It deliberately shows points where many people make mistakes and deepens understanding by exploring the reasons for the errors. Recommended for: Middle school students who dislike or are weak in math and want to start over from the basics. Working adults who want to review middle school math in a short period for SPI preparation or as a hobby. Original price: 2800 yen + tax