It doesn’t add up for Patrick Creagh

We review the ninth of this year's nominees for Book of the Year

Grant applications, musical media and last-minute Olympics training are the topics readers have sent in to the professor's postbox this issue

Mara Kortenkamp, Erin Henning and Anna Maria Hartkopf give us a tour of Polytopia, a home for peculiar polytopes

Never be stumped by a maths problem again, with this crash course from the ever-competent Stephen Muirhead

Print out and make a flexagon