The students Donna Haggerty’s seventh- and eighth-grade math classes at St. Augustine’s of Canterbury School recently were called upon to apply their knowledge to a real-life bridge-building project.
By: Sara Peters
The architect is resketching and erasing, trying to figure out how to make the bridge high enough for tall masted ships to sail under.
The carpenters and masons mold lumber and bricks into the image on the blueprint spread before them.
The transportation chief rages about the price of supplies being raised once again, while the accountant insists they are reaching the limit of their budget.
The project director tries to get all working as a team, and counts the days remaining to complete construction under deadline.
It may sound like another day at the worksite, but it’s actually Donna Haggerty’s seventh- and eighth-grade math students at St. Augustine’s of Canterbury School.
The students recently were called upon to apply their geometry and arithmetic knowledge to a real-life bridge-building project. The classes broke into construction teams and built bridges out of toothpicks, glue and a smidgen of scotch tape.
"Every day in math, I hear ‘How am I going to use this in real life?’ " said Ms. Haggerty. "This was a hands-on way to teach abstract theories. They really got to see how things work."
The building of these bridges was a 10-day process. The first two days were spent studying bridges and discussing why different designs were successful. The students then broke into teams. Each group had its own group of occupations including architect, project director, accountant, transportation chief and carpenter.
The preliminary work was done by the architect, who designed the bridge and drew diagrams of their vision from different angles. The project director then took the architects diagrams, and supervised the construction of the bridge. The accountant kept records of all of the group’s expenditures, ensuring that they remained within their budget. The transportation chief, the only group member permitted to leave the "worksite," was in charge of purchasing the necessary supplies, and the carpenter did the actual construction. No one but the carpenter was permitted to put his hands on the bridge during building, because as Ms. Haggerty explained "the union wouldn’t like it." This method ensured that each student would participate fully in the project.
"This is the first time they’ve worked in groups in a really cooperative way," said Ms. Haggerty.
However, she added some twists and turns to make the tasks of working together and completing construction a bit complicated.
The bridge had to meet some very detailed specifications, and the group’s score depended heavily on how well they met them. Each group was given a strict budget. No member of the team was permitted to do another’s job. The group lost points if the final structure differed significantly from the original blueprints designed by the architect. Only supplies purchased from Ms. Haggerty’s lumber company could be used. Ms. Haggerty even raised the prices of building supplies half way through construction.
And then there were the fines. If the architect did not believe that the bridge was matching the original design, and tried to put their own hands to work in the construction, the group was fined. If anyone but the transportation chief left the work site, the group was fined. If the bridge was not completed in the allotted time, the group was fined. If the group was arguing or causing a disruption, the group was fined.
Yet, despite the challenges the students felt that the fun and the learning experience was worth the work. "It was a good trade-off," said Lorraine Jablonsky, the transportation chief of the second-place winning bridge.
Each bridge differed greatly from the others. Architect Jason Duggan and his team won third place for his bridge, which was a flat bridge with no guide rails that bent slightly under weight, invoking images of stepping carefully across a deep chasm with crocodiles snapping at the bottom.
"I thought in my mind that if the bridge can bend, it won’t break as easily," said Jason, who was pleased by how well his carpenter translated his idea from paper to toothpicks. "That’s just what I had in mind. Everything I wanted to put on it is there. We got full points for that."
Jason’s model did provide enough bend-and-give that it could hold a great deal of weight. Unfortunately, the bridge still had some drawbacks.
"We blew on it, and the whole thing flipped over," said Jason.
The first- and second-place bridges were more traditional designs than Jason’s, yet there were still surprises. Both bridges held all of the gram masses Ms. Haggerty had at her disposal, but one group inched ahead on points for meeting other specifications. The blue ribbon winning bridge used far fewer supplies than the other bridges, gaining strength from an intricate design, rather than from large bundles of toothpicks.
"We were all surprised," said Ms. Haggerty. "I thought that (the second-place bridge) would hold more weight.
"I would never have thought that toothpicks could hold so much," agreed carpenter Richie LaPera.
The student engineers and their teacher all agreed that the project was a success, and look forward to doing another one. "This project encompassed a lot of different things," said Ms. Haggerty. "It made things come alive for them."
Richie put it more simply. "It was fun," he said. "We all had fun."