A Japanese toy company unveiled Thursday the world’s smallest Rubik’s Cube, with the fully functional six-sided puzzle so tiny it can hide under a fingertip. Using advanced metal processing technology, MegaHouse Corp., a subsidiary of Bandai Co., created a mini cube smaller than one-tenth the size of the standard model, with the length of each face only measuring around 5 millimeters and each square around 1.6 mm. The “World’s Record Smallest Rubik’s Cube,” weighing about 0.3 gram, is priced at 777,777 yen ($5,300). Orders can be made on the company’s online store from Thursday, with plans to …