WASHINGTON - In an unusual day at the office for a president, Barack Obama played with robots and talked to children instead of Cabinet secretaries or foreign ministers.
"I also shot a marshmallow through an air gun, which was very exciting," Obama said.
More than 100 students from 45 states attended the second White House Science Fair Tuesday. The winners of science, technology, engineering and math competitions exhibited more than 30 projects.
The president used Joey Hudy's Extreme Marshmallow Cannon, which was set up in the state dining room.
The 14-year-old boy from Phoenix said his invention can shoot a marshmallow 117 feet. He said he has always built things but never something "this serious."
Obama noted that the science fair was taking place two days after the Super Bowl .
"I've said this many times – is if we are recognizing athletic achievement, then we should also be recognizing academic achievement and science achievement. If we invite the team that wins the Super Bowl to the White House, then we need to invite some science fair winners to the White House as well," he said to applause.
Detroit students at the Paul Robeson/Malcolm X Academy Lucas Cain Beal, Jayla Mae Dogan and Ashley Cassie Thomas, all 13, built the same project for the second time and won the Excellence in Engineering Award at the 2012 Michigan Regional Competition. They built a model of an energy-efficient city. The first model was destroyed in a fire that also destroyed their school.
"Now, as I was walking around the science fair, I was thinking back to when I was your age. And basically, you guys put me to shame," Obama said to the inventors, their parents and teachers in an East Room speech.
Isis Thompson, 12, and Ma'Kese Wesley, 11, and their robotics team came up with a lunchbox that uses UV-light to sanitize food. They study at the African Centered Education Campus in Kansas City, Mo.
Despite inventing something that put the president "to shame," Isis said she does not want such an important job as being president.
"When I grow up, I want to be a rapper because that is kind of coming along," she said. Her Pan B is to be a dentist. Ma'Kese wants to be a doctor.