Rubik's Cube, the toy believed to be a best-selling puzzle game of all time, has turned 40.
Google has celebrated the 40th birthday anniversary of the game with an animated doodle that allows users to try and solve the puzzle online.
Rubik's Cube was invented in 1974 by Erno Rubik, a Hungarian architect, who wanted a working model to help explain three-dimensional geometry.
He fashioned the cube himself, hand-carving the device. It took him one month before he was able to solve the Cube for himself.
The puzzle game was licensed by the Ideal Toy Corp in 1980, and since then it has sold more than 350,000 units, making it the biggest-selling puzzle toy of all time.
The cube's six faces are each made up of nine stickered squares with each row and column independently manipulable around a central pivot.
The aim of the puzzle is to return the cube to its original configuration, with each face one colour: red, blue, white, gree, yellow and orange.
