WASHINGTON, D.C. -- President Obama spent part of the day Tuesday hanging out with some of the nation's smartest kids, including one from Phoenix.
Dozens of students attended this year's White House Science Fair.
These were students from across the country who had won competitions in science, technology, engineering, and math.
The President got to take a look at what these kids had come up with.
Joey Hudy, 14, of Phoenix, invented an extreme marshmallow cannon that shoots marshmallows through the air.
"This is basically just an air cannon so it uses compressed air. I pump it up with a bike pump," explained the student at Canyon Springs School in Anthem.
Hudy, who has been diagnosed with Asperger syndrome, beat out thousands of kids to get to the White House science fair.
Hudy's mother Julie says, "He's just a different kid when he's building and when he's presenting to people."
According to Hudy's father, "Asberger is a high functioning autism, which quite often children who have that will gravitate to a certain skill and for him it's been the science and technology, the electronics."
Hudy started a company with a website to sell his inventions. It's called Look What Joey's Making.
This is the second year President Obama has hosted the White House Science fair.
The President says if he can host winning athletic teams, he should also host winning scientists at the White House.