One of the most iconic toys (and sources of frustration for many) is the Rubik's Cube. The Rubik's cube did not have its origins as a toy but was created by Ernő Rubik to solve the structural issues of moving parts without the object falling apart. He did not realize it was a puzzle until he scrambled the pieces and then took more than a month to restore it. 

It is no surprise that these toys are challenging. The cubes have 43,252,003,274,289,856,000 possible combinations (just over 43 quintillion for short)! Impresively there are people out there who compete for solve times (called SpeedCubing) and record times have gone from 22.95 seconds in 1982 by Minh Thai down to 7.56 seconds in 2015 by Feliks Zemdegs. 

The toy has even spawned various sizes including a 10x10 cube. Too many sides? Try a pyramid "cube". Not enough side? Try the Pentagonal Dodecahedron variant!

The iconic toy was on every kids Christmas wishlish. Between 1980 and 1983 200 million cubes were sold!

For the curious, how does a Rubik's Cube work? This video has a great breakdown of how the internal mechanisms work: