President Barack Obama looks over a robotic arm built by Easton LaChappelle, 17, from Durango, Colo., left, during the White House Science Fair, Monday, April 22, 2013, in the State Din

 

              President Barack Obama looks over a robotic arm built by Easton LaChappelle, 17, from Durango, Colo., left, during the White House Science Fair, Monday, April 22, 2013, in the State Din
President Barack Obama looks over a robotic arm built by Easton LaChappelle, 17, from Durango, Colo., left, during the White House Science Fair, Monday, April 22, 2013, in the State Dining Room of the White House in Washington. (AP Photo/Pablo Martinez Monsivais)