Online games can not only entertain but also provide valuable data for researchers tackling computer-vision and other tough computational problems. (p. 170)

Solving puzzles such as TipOver and River Crossing can be surprisingly difficult.

A skein of intriguing mathematical objects comes out of an evening devoted to knitting, crocheting, and other crafts.

A polyhedron with seven faces, 14 vertexes, 21 edges, and a hole makes an intriguing lamp.

A New Orleans sculptor and his tetrahedron-based artworks survived Hurricane Katrina.

Switches in train track layouts lead to a tangled math problem.

Hiding a coin in a cake offers a lucky slice and a tantalizing math problem.