Mathman 18 -
Washington County History


Terrain: Mostly indoors.  Outdoor trail is pretty flat.

Difficulty: Depends on math ability.  It will take quite a while if you do the matrices by hand.

Placed by The Dragon (Mathman) on December 22, 2005

Location: West Bend, Washington County, WI

Materials needed: Personal stamp, stamp pad, calculator (?), these clues, map of West Bend

Dragon's Home Page
Mathman Home Page


Students and parents of students should read my introduction to letterboxing before seeking the boxes.


This box is the eighteenth in a series of letterboxes with mathematical clues.  The boxes are intended for both regular letterboxers and my students.  This box was created for my 2005 Advanced Algebra for Freshmen class for extra credit.  Since Mathman 2 is dangerous to do during winter, I wanted to have an alternative matrices letterbox for them to do at the end of the first semester.  As such, this box is very winter friendly, with most of the "grunt work" done indoors.  Once you decode the clues, it shouldn't take more than 20 minutes outside to find the box, stamp up, and return to the car.  The indoor part however, may take a couple of hours as it may take some time to find the numbers you need and then to decode the matrices.

These clues rely heavily on the use of matrices to encode/decode clues.  Go to this page to learn how to do this on a free graphics calculator simulator or to do it by hand.


Be sure to read through all the clues before looking for the box so you know what is expected of you.

Go to the Old Courthouse Museum at 320 S. 5th Avenue in West Bend, WI.  There is parking in the back, but you must enter off of Chestnut.  The main museum is free, but there is a donation box if you care to contribute.  There is a fee to see the jailhouse, but this letterbox doesn't require you to go through the jailhouse.  You might also want to check out the art museum across 6th Ave. as well, especially to do Mathman 23).


Entrance to the Old Courthouse Museum is in the front.  You can go here to check when the museum is open.  When I went during operating hours, the door was locked, but the staff opened it after I knocked, so don't give up if you find it locked during hours!


I wanted people to tour around the museum to collect various bits of information to be used to decipher the matrix clues, but the museum changes the exhibits more than I anticipated.  Therefore I am including photos of the exhibits I found to make the clues.  Just click on the links in the clues below.  You can use them to solve the box.  I would still encourage you to visit on your way to the box. If you find a problem, please let me know!


Clue 1:
Find the math textbook that is open to "Chapter VI: United States Money and Other Decimals."  Read about US money and mills.  Although this textbook is old and you don't hear much about mills in school anymore, mills are still used in various industries!  In fact, there is one case where you run into the use of mills almost on a daily basis because the industry is forced to force them on you by law.  Think, where do you see mills used in a posted price? _____________________________

Now that you've read the lesson, here's some homework to do:

Find how much money you would have if you added the following:

2 dollars 8 cents 3 mills
1 dollar 9 mills


Take the four digits of your answer and place one each in the following (de)coding matrix to decode the first message (Ignore decimals.).  Always write the message in the space provided at the end of the clues.

Clue 2:
Probably one of the coolest exhibits in the museum is the 1913 Harley Davidson 9G Forecar.  Of the 6732 9E's made in 1913, how many were turned into 9Gs? ______  This will be the first two digits used in the matrix below.  To get the other two, look around and find the price of gasoline "to-day": ____ cents!  Now rev up your engines and decode away!


Clue 3:
I've heard of bottled water, but canned water???!!!  Why would they can water? 



What year is the canned water from? ______ 

From water to beer.  What year did Geotter begin commercial brewing in West Bend? _______

Enter the four digits of the canned water year as the four exponents  in the numerator of the following problem (fill in the 4 blanks).  Then reverse the order of the four digits of the brewery year and place them as the four exponents in the denominator of the following problem:

Simplify the expression (remember, no negative exponents allowed!).  Enter the four exponents in the simplified answer as the four numbers that make up the next (de)coding matrix:


Clue 4:
Even Lewis and Clark used expensive "Mathematical Instruments". How expensive was their most expensive "Mathematical Instrument" the chronometer? _____ (Makes you think graphic calculators are cheap!)


They traveled under a different flag than we do today.  How many stars were on the flag they would've taken (see flag replica)? _____


Multiply these two numbers together to get a four digit number, and enter each digit into the (de)coding matrix below and decode the message:

Clue 5:
Find the Self-winding Clock and read about this interesting timepiece.  Write the four digits of the year the company was formed in New York into the (de)coding matrix and decode the message:

Clue 6:
Find the picture of the "Spirit of Washington County Wisconsin" and read about its history.  Take the year the savings bonds were collected in ______ minus the number of "minute men" that helped collect the bond money _____.  What is your four digit result? _______  Enter these four digits into the following (de)coding matrix and decipher the clue!


Clue 7:
The room about the ancient Indians of Wisconsin and Washington county is very informative.  Take time to listen to the Indian music while reading about the effigy mounds at the nearby Lizard Mound Park.  If you are visiting during non-winter months, you might want to take a trip to the park to experience the mounds yourself!  (You'll never know what interesting things you might find there if you look in the right spots!)

Did you know that Black Hawk led his people through Wisconsin?  If you browse The Story of Wisconsin Indians you can find the year of Black Hawk's route through Wisconsin.  Enter the four digits into the (de)coding matrix below to get another clue!


Clue 8:
Each of the determinants you calculate below are two digit numbers, so you will have four digits to enter in the (de)coding matrix below. Put them in in the order you have them into the (de)coding matrix, keeping the negative sign with the digit that it is in front of.

In what year would you find a prayer book in a ladies' bag?  _________
Put the digits of this year in the following matrix and find its determinant:

In what year would you find an MP3 player in a ladies' bag?  _________
Put the digits of this year in the following matrix and find its determinant:


Clue 9:
Find out what a "beetle" is used for: __________________________________________
What year is the "beetle" displayed from? ______

Also, there is a neat hitching post that used to be in front of a doctor's office on _____ Poplar St.

Take the "beetle" year and add it to the doctor's street number and you get: _______

Enter these four digits below and decode the following without a hitch!

Clue 10:
Did you know that at one time, Washington and Ozaukee Countries were divided east-west instead of north-south! The old map of the counties isn't that old however.  The date on the map does however look like a subtraction problem, so do the math and enter the four digits into the following (de)coding matrix to finish the clues!

To find the box, write the decoded texts on the corresponding lines below.  Then follow the clues!

Clues to the box:
Go to Ridge Run Park.

Enter just north of UWWC off University Dr.

Park in lower lot.






















There you will find a large fallen tree or branch.  One of its broken arms is sticking up at you about waist high about six feet from the back of the tree.  The box is hiding in one of the various cavities of this branch.  Remove the loose bark in the cavity of this arm to find the box.  After stamping up, replace the box and the loose bark so the box canít be seen, but make it look natural.


Good luck!

Before you set out read the waiver of responsibility and disclaimer.

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