My daughter is in 6th grade. She likes mathematics, i.e., she likes to learn mathematics at school, is also good at what she has learned at school and is rather quick at picking new things. However, she is currently only limited to text books, which I feel are not inspirational, and don't make you fall in love with mathematics. I am looking for some books that may do exactly this for her age group. (i.e., it should be fun to read while showing the real beauty of mathematics.)
For example, topics like the golden ratio, and symmetry are simple enough and fun to explain, but at the same time can be used to show how mathematics is all around us or to show even beauty can be to some extent quantified.
I have looked at some other questions, some are really for kids who are too young, or adults. (Books in German or with German translation are a plus).