Truncated hexahedrons and octahedrons hang from the ceiling in Mary Jo Messenger's classroom at Centennial High School, but the real eye-catcher is the fractile stella octangula.
"It means 'Like a star,'" freshman honors geometry student Pnina Laric, 14, said. "We stellated each side."
Translation: the basic stella octangula is a 24-faced figure created by placing a tetrahedron on each face of an octahedron. Students fill in additional tetrahedrons and as they do, the figure approachesthe shape of a cube.
Putting it together took 85 students two school days and 10 students a third day, and by the time they finished they had gone punchy. But they did it, says freshman Aarti Shastry, 14, "because we love math."
The ability to get students to love geometry is one reason Messenger will join 107 other secondary school science and math teachers who are scheduled to receive Presidential Awards for Excellence in Science and Mathematics Teaching this week.
The awards are given annually to one science and one math teacher fromeach state and U.S. territories. Each winner receives a $7,500 grantand a week of activities in Washington, including congratulations from President Bush.
Howard County has two presidential award winners this school year. Carol Cobb, a second-grade teacher at Elkridge Elementary School, received one of 108 awards presented to elementary science and math teachers in October 1991.
Messenger teaches honorsgeometry and concepts of algebra this year, but her heart belongs todata analysis. As a student at Maryville College, where she graduated with a bachelor's degree in math in 1967, she hung out in the computer lab. She considered a career in computer science, but "I didn't like the isolation. I wanted to work with people."
She earned a master's degree in computers in education from University of Maryland in1983.
She says she always liked math, even the dry Euclidean theorems that defined geometry for her and her classmates at Walter Johnson High School in Bethesda. Messenger's students learn that the square of the hypotenuse is equal to the sum of the squares of the two sides, but they also learn about cubes by making cubes.
That explainsthe tessellations. Messenger was in New Orleans last year at a National Council of Teachers of Mathematics convention and had dinner at KPaul's restaurant. She looked up and saw the ceiling tiles decoratedwith drawings and signatures, which prompted an idea.
"I thought,if they can do it at K Paul's, we can certainly do it at Centennial High School," she says.
The result was ceiling tiles covered with brightly painted tessellations, repeated geometric patterns that formmosaics. Messenger says former students have come through the room, looked up at the ceiling and complained, "We never got to do that."
Messenger, who heads the school's math department, is using the $7,500 grant to send Centennial math teachers to conferences. Teachers need time to talk to each other and to plan together, particularly as their roles are changing, she says.
"For most of us, it's hard to let go of the old," she says. But new emphases on communication, reasoning, problem solving and connections will require teachers to become coaches rather than lecturers, she adds. Teachers will give students the basic tools they need, get them involved in problems and let them use the tools to solve the problems.
Messenger has been teaching in county schools since 1979. She took a teaching job in Anne Arundel County when she and her husband, Scrib Messenger, a linguistics expert, moved to the area in 1977. In Howard County, she started teaching at Atholton, transferred to Howard High in 1982 and to Centennial in 1988.
The couple has two daughters, one employed by Chevy ChaseBank and one a student at Howard Community College.