Clemens Crossing Elementary School first-grader Victoria Miceli looked upward and wrinkled her brow as she pondered the math problem: 15 + 8. She methodically bent her fingers to count and heaved a big sigh.
"Twenty-three," the 7-year-old finally said. She smiled when she learned she had answered correctly and reached into a bag for her prize: a small plastic toy.
Clemens Crossing's gym turned into a carnival Friday, when students turned out for a Math Fair in which older children created games for their younger peers. Third-, fourth- and fifth-graders stood at tables calling for others to play games of different types, including "The Mean Bean Machine" and "Pick a Pingpong." One game required students to estimate the height they can jump.
Victoria, wearing a big white bow to keep her long brown hair out of her face, played a game akin to bowling in which she aimed a rubber ball at plastic cups numbered zero through 10. She struck three cups and added the numbers 9, 6 and 8 to come up with the answer.
"I learned that when you add numbers, you can use your fingers," she said. "And I learned you don't have to count with your fingers. You can use your head."
Kathy Bonebreak, the school's guidance counselor, came up with the idea for the Math Fair to help students brush up on their math skills and to develop their confidence, self-esteem and other social skills through creativity, organization and responsibility.
Students had to devise games that would use math and also be entertaining. They received approval for their games from a math fair committee, then worked with their classmates to complete the projects.
"The children were very organized," said Mrs. Bonebreak, beaming about how students pulled everything together. "They learned teamwork and cooperation, and they had to communicate with one another by explaining the games to the younger children."
Many students said that one lesson learned is that they had to finish what they started.
"If you put your mind to something, you could make something this nice so kids could have fun," said fourth-grader Steve Krakauer, 10, standing in front of his creation, "Math Money," patterned after popular board games such as "Life."
He designed the game for kindergartners who rolled a die and moved quarters, pennies and other coins as playing pieces. Then the kindergartners answered questions such as "How much is a quarter worth?" and "Which president is on a nickel?"
Steve said he felt proud showing younger students how to play the game. "I felt like a teacher," he said. "I think the kids are learning and they're refreshing the facts they already knew."
Other student inventors said the younger children had good math skills. "So far, they've been doing pretty good," said 9-year-old Ryan Ashford, whose invention was "Marble Math." "I think they've been listening to their teachers."
Younger students each came with a plastic bag containing tickets to the games. They earned the tickets in classes as a reward for working quietly or completing morning drills.
Seven-year-old Agata Kaczanowska played a game called "Mathematical Horses," an idea conjured up by third-grader Erica Finkel. Hidden beneath a half-dozen rows of plastic 3-inch horses were math problems, such as 2 + 5, 9 + 1 and 8 + 2. Students had to answer correctly to get a prize.
Erica, 10, came up with the idea because she loves horses and has a collection of plastic ones at home that her grandmother gave to her.
Eight-year-old Iris Shih, a third-grader, offered a game called "Math Tepee," which required students to roll dice and solve math problems by moving little yellow construction paper tepees up a chain of numbers. "I'm reading a little about the Indians, so I decided to do something with Indians," she explained.
Asked if she learned anything at the math fair, Iris raised her index finger and said earnestly, "I learned one thing: If you talk too much, your throat gets dry quickly."