We provide books & magazines for chemistry learners of all ages, from elementary school to graduate school.

But I surprised myself by setting aside every book and special-issue magazine I came across that had to do with putting. It occurred to me: What if I’d been wrong? What if putting was a riddle ...

She has six boxes of books and a box of magazine she wants to move. Each box shows how many items there are in it. Eilidh makes the space she needs by selling off some books to one customer ...