Objective:
Students will draw or construct a replica of a local bridge using a scale. They will include in a laboratory report information about the bridge regarding ratio, proportion, and symmetry as well as a hypothesis. See appendix 3 for suggestions on local bridges.
Procedure:
This activity will require a field trip to a local bridge. Students will work in teams as described above.
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Students will know how to scale using ratios and proportion and will be able to determine symmetry.
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Students will examine the bridge for symmetry, ratios, and proportion at the site.
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Students will use measurements, such as tape measure, ruler, compass, string, camera, sketch pad, and pencils to record the dynamics of the bridge and then translate the information to a scaled drawing or model the bridge by scale out of sticks or other medium back at the school.
Sample Lesson
One way of executing this lesson using the above described teaching strategies is to first have students discuss general information about bridges during a report out with attention to covering essential topics as scale, ratio, proportion, and symmetry. Have students brainstorm about what they predict what they will find when they examine the bridge they have chosen from a list of available bridges to visit provided by the teacher. Where will they predict they will find symmetry on the bridge, where will they find ratios and proportions? If basic information is not revealed by the students then the teacher would provide guidance and hints for its discovery.
Students would decide what will be taken out to the field trip such as ruler, tape measure, sketch pad, pencils, camera, or whatever they deem needed. Guidance would be needed so that nothing is left behind. At the site have students collect information and data to bring back to the classroom. Moderate and guide students so that all information necessary is recorded to avoid a second trip. It is suggested that teachers visit the site of the bridge beforehand.
At this time remind students that they need to formulate a hypothesis or problem statement and should consider this as they as taking measurements. Back at the classroom, some students will decide to work on the engineering aspect of the project and sketch a scaled detailed replica of the bridge or construct the bridge out of sticks or papier mache. Other students will begin working on the hypothesis and laboratory report. The two groups should see the need to integrate, work together, and share ideas as they complete their aspect of the project.
Assessment
Laboratory Report
A sample hypothesis or problem statement might concern changing the scale to see how ratios and proportions are affected or vice versa or perhaps determine how the bridge might look if it was not symmetrical. Students may also have discovered an attribute about the bridge that they would like to hypothesize about. See appendix 1 for a sample Laboratory Report outline but any would suffice.
