First Lady Michelle Obama, Sasha, Malia and Marian Robinson watch students perform a Rubik's Cube demonstration during their visit the Xi'an City Wall, China

First Lady Michelle Obama, Sasha, Malia and Marian Robinson watch students perform a Rubik's Cube demonstration during their visit the Xi'an City Wall, China on March 24, 2014. (Official White House Photo by Amanda Lucidon)