Main Question or Discussion Point
My niece is 10 years old and taking algebra 1 this year in school. She's very gifted and driven to pursue math. I want to give her a book that is going to introduce her to higher math concepts like sets and basic proofs, but I don't know what kind of book would be appropriate for her. She doesn't have much of a problem digesting Tolkien, so I doubt there will be a language barrier to higher level maths. Any ideas?