Tacoma Narrows Bridge Lesson Plans
Math and Social Studies
Math & Social Science
Aftermath – A New Beginning: 1940 – 1950
Galloping Gertie lasted only four months and seven days before
collapsing into Puget Sound in November, 1940. It became clear during
those four months, however, that the Narrows Bridge was far more
poplar than the expert’s traffic surveys had predicted. In
its first four months, the bridge’s revenues fully justified
a $10 million bridge, one that would have been four lanes wide,
strong, sound, safe and still spanning the Narrows. For the residents
of Tacoma and the Olympic Peninsula, the collapse of the bridge
was a tragedy. Merchants on both sides lost income, and the military’s
vital link between the Bremerton Navy Yard and the Army’s
installations at McChord Field and Camp Lewis was all but severed.
It took ten years before another bridge was built, due to insurance
squabbles, the need for extensive testing, and the advent of World
War II. But once the bridge was finally built, the number of vehicle
crossings of the Narrows increased dramatically. Students will chart
the traffic patterns across the Narrows over time, and use their
graphs, prior historical knowledge and reasoning skills to answer
the discussion questions listed below.
Lesson Objectives
As a result of this lesson, students will be able
to:
 Understand and apply properties of addition, subtraction, multiplication
and division to real world problems;
 Understand and apply strategies and tools as appropriate to
tasks involving the four basic operations on integers and nonnegative
rational numbers;
 Understand and apply various data display techniques, including
bar, circle and line graphs;
 Understand how to devise a plan to solve problems.
 Use graphs to describe trends, compare, and interpret relationships
from data.
 Understand how mathematical ideas connect within mathematics,
to other subject areas, and to reallife situations.
Time: Two days or class periods.
Materials Needed:
 Graph paper, rulers, calculators, drawing paper, and/or computers
with PowerPoint and/or Excel. Provide students with data table
shown below:
Year 
No. of Vehicles Annually 
Vehicles Daily Avg. 
Percent Change
+ or  
1930 ferry 
171,993 


1935 ferry 
165,724 


1939 ferry 
205,842 


1940 bridge
71117 
265,748 


1940 ferry 
144,587 


1945 ferry 
480,009 


1950 ferry 
593,871 


1950 bridge
1014  1231 
280,464 


1955 bridge 
1,715,135 


1960 bridge 
2,269,570 


1965 bridge 
4,112,455 


1970 bridge 
7,724,860 


1975 bridge 



1980 bridge 
14,225,145 


1985 bridge 



1990 bridge 
24,229,145 


1995 bridge 



2000 bridge 
32,120,000 






Lesson Steps
Day One:
1. Using the figures provided above, calculate
the average number of vehicles crossing the Tacoma Narrows each
day at fiveyear intervals beginning in 1930. For intervals that
do not have yearly totals, calculate the average of the two surrounding
intervals, and use that figure.
2. Calculate the percentage of growth
from one interval to the next.
3. Make a graph showing the increasing numbers
of vehicles crossing the Tacoma Narrows from 1930 to 2000.
4. Make another graph showing the rate of increase
for each interval between 1930 and 2000.
5. Bring students together in a group
and speculate on the reasons why the graph looks the way it does.
See Tacoma Narrows Bridge website for more background information.
6. Tell students about the status of current
construction on the second Narrows Bridge. Ask them what
the implications are for future growth on the Olympic Peninsula.
Related links on this site:
Evaluation
Evaluate students’ calculations and graphs based on the same
standards you regularly use in your own classroom. top
