Fifth-grader Will Cramer demonstrates his Bet Fair Machine, which releases a prize when strings are pulled, at the Invention Fair of St. Cletus School. | Jane Michaels—Sun-Times Media

Brady Bourjaily, a fifth-grade student at St. Cletus, enjoys sharing about his invention to water a Christmas tree. | Jane Michaels— Sun-Times Media

Fifth-grader Bradley Jaunich shows how his Laundry Detergent Helper works at the Invention Fair at St. Cletus School in La Grange. | Photo courtesy of Nate Banos

Bella Dziak, a fifth-grader at St. Cletus School in La Grange explains how a step stool she built helps her dog, Fluffy, look out the window. | Photo courtesy of Nate Banos

Fifth-grader Arianna Klapsis invented the Paw Paw to help her dog, Mia, pull a string to get some chow. | Photo courtesy of Nate Banos

Alex Morlock explains how to use his Water Shovel as one of the entries in the fifth-graders’ Invention Fair at St. Cletus School in La Grange. | Photo courtesy of Nate Banos

Fifth-grader Christian Hagn shows how his shoe cleaning machine works during the Invention Fair at St. Cletus School in La Grange. | Jane Michaels—Sun-Times Media