This Math in the News explores the construction of the iconic landmark the Washington Monument and its recent renovations due to the 2011 earthquake. Students will be able to convert dollar values based on inflation and determine the combined expense of the Washington Monument between construction and recent renovations.

1. Issue
97
The Washington Monument: Repaired

2. The Washington
Monument was
constructed in honor of
its namesake and
founding father George
Washington. It was
intended to evoke the
awe and respect the
nation felt for its first
leader. (Source:
National Park Service) Source: National Park Service

3. The monument went
through two phases of
construction: one
private (1848-1854)
and one public (1876-
1884).The ambitious
design made it
expensive to build, and
funds ran out until
Congress assumed
responsibility in 1876.
(Source:
National Park Service)

4. The monument was dedicated on February 21, 1885. At
the time of completion, it was the tallest building in the
world at 555 feet, 5 1/8 inches.
(Source: National Park Service)

5. Check out this short video for a
little more history on the iconic
Washington Monument.

6. On August 23, 2011,
the DC Metropolitan
area sustained an
earthquake with a
magnitude of 5.8.The
earthquake caused
considerable damage
to the Washington
Monument.

7. The monument was not
built to sustain earthquakes,
in part due to its rigid stone
structure and in part due to
its high center of gravity.
Survey of the damage
concluded the monument
needed extensive repairs
and was closed indefinitely.
(See Math in the News:
Issue 31)
Cracks in the stone of the monument after
the 2011 earthquake, National Park Service

8. After nearly 3 years of repairs, the monument is
set to reopen on May 12, 2014.
National Park Service Earth Cam

9. A considerable amount of money has been
spent on the Washington Monument since
its beginnings nearly 150 years ago. Let’s
take a look at the costs of building the
structure and the cost of repairs.

10. The total cost of constructing the
Washington Monument was $1,187,710 in
1884. Keep in mind, due to inflation, $1 in
1884 is equivalent to $23.81 today.

11. The total costs of reconstructing the
Washington Monument after the 2011
earthquake added up to $15,000,000.
(Source: Campaign for National Mall)

12. With the information we have, we can
answer the question: What was the cost of
constructing the monument relative to the
cost of the earthquake repairs?

13. First, let’s set up a proportion to
determine the cost of initial construction
in today’s dollars. Remember, $1 in 1884
equals $23.81 today and the monument
took $1,187,710 to build.

14.  How would you say the proportion in
words?
“$1 is to $23.81 as $1,187, 710 is to x."
 How would you write the proportion
using mathematical symbols?
1
23.81
=
1,187,710
x
1
23.81
=
1,187,710
x

15. How can we solve this proportion?
Cross Multiply
1
23.81
=
1,187,710
x

16. 1• x = 1,187,710• 23.81
x = 28279375.1
1
23.81
=
1,187,710
x

17. Accounting for inflation, in today’s
currency, the total cost of the original
construction of the Washington
Monument was $28,279,375.10!

18. In today’s currency, how much more money did it
cost to build the Washington Monument than to
renovate the monument?
Cost of construction – Cost of Renovation
28,279,375.1 – 15,000,000 =
13,279,375.1
Construction of the Washington Monument was
$13,279,375.10 more expensive than the
earthquake renovations.

19. What percent of the cost of the original construction
did it cost to make the repairs?
To find the percentage a part of a whole, we use the
following formula:
Part ÷ Whole = Percent (in decimal form) Cost
of Repairs ÷ Cost of Original Construction =
Percent

20. 15,000,000 ÷ 28,279,375.10 = 0.5304
0.5304 = 53.04%
The cost of repairing the Washington
Monument was 53.04% of the original cost.

21.  Consider the following questions as you
continue to explore the history of the
Washington Monument:
• What other renovations have taken place since the
monument was built?
• How much did those renovations cost (in dollar
amounts in that year, and in current dollar amounts
due to inflation)?
• How much money total has been spent on the
Washington Monument since its construction
began?