Five screw-puzzles by George Hart

Math Gear(s)

by WorksBySolo

Math Spinner Toy

by christinachun

Polyhedra - Hinged Nets and Snap Tiles

by mathgrrl

Seesaw Maths

by Gyrobot

Platonic solid in Euclidean geometry / Platonische Koerper

by nischi

The T-Rex Skull

by MakerBot