(a) a puzzle in the form of a box; (b) Psychology a box with no obvious connection between its door and the opening device, designed to test the…

A mathematical puzzle in which an arithmetical proposition is expressed in letters, each letter standing for one of the ten digits, the task being…

A mathematical puzzle in which an arithmetical proposition is expressed with the ten digits represented by a different letter of the alphabet, the…

A proprietary name for: a three-dimensional puzzle consisting of a multicoloured plastic cube which must be manipulated to adjust the pattern of…

A game designed to exercise the mind, a brain-teaser.