Who hasn't been here: You open up one of those craft or science kits with your kid only to find really bad directions or enough materials to only do the project once. And then ... my favorite ... there are the kits that don't include everything you need so you have to go back out to the store to get that special tube of glue or something.

Connor Bernstein, when he was only 9 years old, decided to do something about it.

Connor, now 15 of Chapel Hill, launched Kits for Kids in 2004 after growing frustrated with all the science kits he brought home. There weren't enough materials. He couldn't repeat the experiment. He couldn't understand the instructions. So he decided to make his own.

Connor, who attends a charter high school in Saxapahaw, started selling his kits at street fairs and craft shows. Sales were steady, he told me, until about two years ago when a connection at UNC's Kenan-Flagler Business School got him into an entrepreneural program at the school normally reserved for graduate students.

"We went over marketing, management, implementation and finances," he said.

From there, Connor started working with a marketing firm in Raleigh to help rebrand the company and come up with a new logo. He's also been working on a new website to launch in time for the CoolKidz Expo, where he'll be an exhibitor this weekend.

Right now, Connor sells four different kits. One lets kids make three different kinds of crystals, for instance. Another shows them how to make slime. They sell for $14.95.

"The idea behind the kits is that they are allowance friendly," he said. "They explain how and why everything works. The instructions are written for kids by kids. Every kit the kids can repeat the experiment at least once. And they don't have to get anything else at all."

In other words, the kits resolve all the problems with the ones that he was so frustrated with at age 9.

Connor hopes to build his business by adding more kits and expanding his customer base. But he also enjoys teaching kids one-on-one about his own love of science. Connor visits classrooms and afterschool programs around the Triangle to show kids that science can be fun.

"I’m really optimistic about it," he said. "It’s really something I’m committed to ... spreading the joy of science. It’s really fun just making a mess in the kitchen, coming up with experiments for kids and sharing it with other kids."

Connor says kids ages 8 to 12 can probably do the experiments independently. Kids ages 4 to 7 also will enjoy them, though will probably need some guidance from an adult. Connor will have some activities at his booth at the CoolKidz Expo so you can see what the kits are all about.

And for more on Kits for Kids, check out its website at kitsforkids.com.