Remember readin, riting and rithmatic? According to our Rethinking Education panelists, the three Rs need to be joined by a C — for computer science — or the US risks getting run over by more progressive nations. That was the opinion of Rodrigo Arboleda from the One Laptop Per Child organization, who spoke at Engadget Expand along with Jeff Branson from SparkFun and Pat Yongpradit from Code.org.