The Usefulness of Useless Knowledge by Robbert Dijkgraaf, ISBN 9780691174761

A Mathematician’s Apology by G. H. Hardy, ISBN 1684221851

Mathematics without apologies: Portrait of a Problematic Vocation by Michael Harris, ISBN 0691175837

How to Bake Pi: An Edible Exploration of the Mathematics of Mathematics by Eugenia Cheng, ISBN 0465097677

Math with Bad Drawings: Illuminating the Ideas That Shape Our Reality by Ben Orlin ISBN 0316509035

Beyond Infinity: An Expedition to the Outer Limits of Mathematics by Eugenia Cheng, ISBN 0465094813

Have you ever wondered?

Which number do you like better, π or e? Why?

The area of a triangle is a half of its base times height. Can you prove this without a word?

Think of wooden puzzles involving tessellations, both of the Euclidean and the hyperbolic plane (e.g. puzzles related to M.C. Escher’s paintings, link above).

Are there different infinities? How many different infinities do we have?

Why do topologists get donuts and coffee cups confused?

My brother’s brother is my brother, but my father’s father is not my father, right?