Some students turned to robots to learn about climate change.
Students competed at the Central Texas First Lego League Tournament on Saturday.
The idea was to prove that their robotic designs and research could improve the world and provide environmental benefits.
"I think it's a lot harder than I could do. And I'm delighted that they can find out that they can do it. We all have to learn that we can do more than we've been doing," Massachusetts Institute of Technology professor Woodie Flowers said.
More than 500 elementary students participated in the competition.
They were competing for the chance to attend the 2009 World Festival in Atlanta.
