Kids from all over the state head to Cedar Rapids this weekend to show off their plans for cities of the future. Coordinator Ron Griffith says they’re young, but they’re smart.He calls the kids “science nerds,” already smarter than us, though only seventh and eighth-graders are allowed to participate. This is the fourth year Iowa’s participated in the national “Future City” competition, and this year’s theme is designing features with senior citizens in mind. Griffith says the work begins with a computer program many kids play as a game. They use “Sim City 3000,” create a city of the future using that software, then write an essay and build a model of their imaginary city which they’ll bring to this weekend’s competition. The in-person presentation will require kids to stand up and tell the audience of their plans on Saturday, and Griffith says it’s quite a range of skills, in all. Looking at alumni of the competition, the kids grow up to enter professional careers from doctor to lawyer to professional engineer — but he says this range is skills will benefit them in any career. The public can come watch the show by 180 seventh- and 8th-grade students, this Saturday at Cedar Rapids Prairie Middle School.