David Seligman likes wearing a kippah during morning prayers. But it doesn't always stay put.

"When I bend my head back, my kippah falls to the ground," explains the kindergartner. "I always get annoyed."

His solution to the problem: The Magic Kippah Keeper, a large cloth crown that encircles the head like a high fence and prevents errant kippot from escaping.

Seligman's invention is one of 175 ingenious devices created by the students of the Jewish Day School of the North Peninsula in Foster City. The school held its first annual Invention Convention the week of March 24 to promote creative thinking in students.

"We've always valued inventive minds in the U.S. — it's a quality that is so prized in American society," says Robin Raphael-Simke, the school's science teacher who organized the event.

Unlike a traditional science fair, coming up with an invention is a project that is accessible to younger students, she explains. "A good science fair project — one where you actually run a controlled experiment — is really involved and requires a certain intellectual capacity. That's something you can start at the sixth-grade level."

Each of the students at the school, from kindergarten to sixth grade, came up with a real-world problem and how to fix it.

One common dilemma for the younger set was the eternal question of how to reach things when you're too short. Oryan Levy, 5, created a pair of pink platform shoes to give her a boost. "My mom was sleeping, and I wanted to get some ice cream," she said.

Another kindergartner designed a pair of rainbow-colored wings.

"I'm very impressed by what they've come up with," said Michele Ban, a fifth-grade teacher at the school who scrutinized the projects as a judge. "Kids are less constrained by ways of thinking than we are as adults — they don't need to censor their ideas."

First place-winning projects included a spray-on Band-Aid, by first-grader Eliot Zubkoff; an automatic toilet-seat lowering device, by third-grader Arielle Storm; and a Velcro system to keep pillows from sliding off the bed at night, by fifth-grader Leah Simke.

To get into the inventor's mindset, students learned about the history of inventions. In a lesson on California history, fourth-graders learned how Levi Strauss created sturdy pants for Gold Rush miners. To promote creative thinking, students also went through exercises such as "alternate uses," where they tried to come up with as many uses they could think of for a common object (for example, a key can also be used as back-scratcher).

Raphael-Simke sees the program as an important way to broaden both her students' perspectives as well as those of outsiders who see Jewish schools as "ghettoizing."

"People think the kids are going to be freaky and detached — that we're in here praying all day. This is a really powerful thing that they are learning — if something doesn't work, they can fix it."