A discussion of numbers, shapes, and logic that you might think you understand but don't (Academic Selection 61)

How to calculate addition and how to find the area of ​​a rectangle are common knowledge learned in elementary school. However, when asked, "Why is 1 + 1 = 2?" or "What is area, anyway?", few people can properly explain it. This book takes up 10 topics from the mathematics of numbers, shapes, and logic that are learned in high school and the first year of university, and provides detailed explanations of these topics that seem obvious but are actually not fully understood.