This is a bundle of books for first to third graders. The third-grade books have been read, so they show some signs of use. [Book Overview] A "reading encyclopedia" that satisfies intellectual curiosity --- Explanations of "why?" and how things work, all with illustrations! --- It helps children understand things in a fun way by explaining their "curiosities" with abundant illustrations, such as "Why are pandas black and white?" and "Where do tears come from?"