WASHINGTON, DC - MARCH 23: U.S. President Barack Obama (R) shakes hands with a group of six-year-old Girls Scouts from Tulsa Oklahoma who designed a battery powered page turner to help people who are paralyzed or have arthritis at the 2015 White House Science Fair March 23, 2015 in Washington, DC. The students are winners of STEM (Science, technology, engineering and math) competitions from across the country (Photo by Aude Guerrucci-Pool/Getty Images)
