THE BRONX - The hallways of the Urban Assembly School for Applied Science & Mathematics in the Bronx were abuzz as 100 sixth-graders built paper helicopters today.

Students designed, built and tested their own helicopters. Organizers say science topics explored during the lesson included the relationship between surface area and descent rate for helicopters and the forces that affect motion of a falling object.

The day-long project is part of Siemens Science Day. The program hosts math and science learning events throughout the city.

Urban Assembly School for Applied Math and Science is just one of about 300 schools across the country who participated in the science day this year.