A calculating tool, the invention of the slide rule was made possible by John Napier’s invention of logarithms, and Edmund Gunter’s invention of logarithmic scales, which slide rules are based upon.
Ernő Rubik invented the cube in 1974 as a tool to help students understand 3d objects, moving parts independently without the mechanism falling apart.
After realizing the possibilities of his puzzle he got a patent and sold it to Ideal. There are many books and videos (now) on solving for us ordinary but curious folk. Read more on Wikipedia, Rubiks, Youcandothecube and Ruwix.